39168763921 has 21 divisors (see below), whose sum is σ = 45776170299. Its totient is φ = 33515040384.

The previous prime is 39168763889. The next prime is 39168764009. The reversal of 39168763921 is 12936786193.

The square root of 39168763921 is 197911.

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

It can be written as a sum of positive squares in only one way, i.e., 38897700625 + 271063296 = 197225^2 + 16464^2 .

It is not a de Polignac number, because 39168763921 - 2⁵ = 39168763889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39168763121) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 67883185 + ... + 67883761.

Almost surely, 2^39168763921 is an apocalyptic number.

39168763921 is the 197911-st square number.

39168763921 is the 98956-th centered octagonal number.

It is an amenable number.

39168763921 is a deficient number, since it is larger than the sum of its proper divisors (6607406378).

39168763921 is an frugal number, since it uses more digits than its factorization.

39168763921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1196 (or 584 counting only the distinct ones).

The product of its digits is 2939328, while the sum is 55.

The spelling of 39168763921 in words is "thirty-nine billion, one hundred sixty-eight million, seven hundred sixty-three thousand, nine hundred twenty-one".