1242653661 has 12 divisors (see below), whose sum is σ = 1795264380. Its totient is φ = 828288000.

The previous prime is 1242653651. The next prime is 1242653701. The reversal of 1242653661 is 1663562421.

It can be written as a sum of positive squares in 2 ways, for example, as 1008380025 + 234273636 = 31755^2 + 15306^2 .

It is not a de Polignac number, because 1242653661 - 2⁹ = 1242653149 is a prime.

It is a super-3 number, since 3×1242653661³ (a number of 28 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242653611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69661 + ... + 85661.

It is an arithmetic number, because the mean of its divisors is an integer number (149605365).

Almost surely, 2^1242653661 is an apocalyptic number.

It is an amenable number.

1242653661 is a deficient number, since it is larger than the sum of its proper divisors (552610719).

1242653661 is a wasteful number, since it uses less digits than its factorization.

1242653661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24636 (or 24633 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 1242653661 is about 35251.2930401141. The cubic root of 1242653661 is about 1075.1029030032.

The spelling of 1242653661 in words is "one billion, two hundred forty-two million, six hundred fifty-three thousand, six hundred sixty-one".