40617968521 has 27 divisors (see below), whose sum is σ = 45311763861. Its totient is φ = 36393106464.

The previous prime is 40617968507. The next prime is 40617968543. The reversal of 40617968521 is 12586971604.

It is a happy number.

The square root of 40617968521 is 201539.

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 168714121 + 40449254400 = 12989^2 + 201120^2 .

It is not a de Polignac number, because 40617968521 - 2⁷ = 40617968393 is a prime.

It is a super-3 number, since 3×40617968521³ (a number of 33 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (40617968551) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 96940050 + ... + 96940468.

Almost surely, 2^40617968521 is an apocalyptic number.

40617968521 is the 201539-th square number.

40617968521 is the 100770-th centered octagonal number.

It is an amenable number.

40617968521 is a deficient number, since it is larger than the sum of its proper divisors (4693795340).

40617968521 is an frugal number, since it uses more digits than its factorization.

40617968521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 938 (or 469 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 49.

Multiplying 40617968521 by its sum of digits (49), we get a square (1990280457529 = 1410773²).

The spelling of 40617968521 in words is "forty billion, six hundred seventeen million, nine hundred sixty-eight thousand, five hundred twenty-one".