39138649575921 has 189 divisors, whose sum is σ = 69302131008201. Its totient is φ = 22029140781648.

The previous prime is 39138649575913. The next prime is 39138649575937. The reversal of 39138649575921 is 12957594683193.

The square root of 39138649575921 is 6256089.

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

39138649575921 is a `hidden beast` number, since 3 + 9 + 1 + 3 + 8 + 6 + 49 + 575 + 9 + 2 + 1 = 666.

It is a tau number, because it is divible by the number of its divisors (189).

It is not a de Polignac number, because 39138649575921 - 2³ = 39138649575913 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 39138649575921.

It is not an unprimeable number, because it can be changed into a prime (39138649595921) by changing a digit.

It is a polite number, since it can be written in 188 ways as a sum of consecutive naturals, for example, 93409664650 + ... + 93409665068.

Almost surely, 2^{39138649575921} is an apocalyptic number.

39138649575921 is the 6256089-th square number.

39138649575921 is the 3128045-th centered octagonal number.

It is an amenable number.

39138649575921 is a deficient number, since it is larger than the sum of its proper divisors (30163481432280).

39138649575921 is an frugal number, since it uses more digits than its factorization.

39138649575921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1028 (or 508 counting only the distinct ones).

The product of its digits is 440899200, while the sum is 72.

The spelling of 39138649575921 in words is "thirty-nine trillion, one hundred thirty-eight billion, six hundred forty-nine million, five hundred seventy-five thousand, nine hundred twenty-one".