1240904653681 has 243 divisors, whose sum is σ = 1810856769057. Its totient is φ = 846965306880.

The previous prime is 1240904653621. The next prime is 1240904653777. The reversal of 1240904653681 is 1863564090421.

The square root of 1240904653681 is 1113959.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 577233738081 + 663670915600 = 759759^2 + 814660^2 .

It is not a de Polignac number, because 1240904653681 - 2⁷ = 1240904653553 is a prime.

It is a super-3 number, since 3×1240904653681³ (a number of 37 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (1240904653621) by changing a digit.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 33537963595 + ... + 33537963631.

Almost surely, 2^{1240904653681} is an apocalyptic number.

1240904653681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1240904653681 is the 1113959-th square number.

1240904653681 is the 556980-th centered octagonal number.

It is an amenable number.

1240904653681 is a deficient number, since it is larger than the sum of its proper divisors (569952115376).

1240904653681 is a wasteful number, since it uses less digits than its factorization.

1240904653681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 49.

Multiplying 1240904653681 by its sum of digits (49), we get a square (60804328030369 = 7797713²).

1240904653681 divided by its sum of digits (49) gives a square (25324584769 = 159137²).

The spelling of 1240904653681 in words is "one trillion, two hundred forty billion, nine hundred four million, six hundred fifty-three thousand, six hundred eighty-one".