64920251 has 6 divisors (see below), whose sum is σ = 71358756. Its totient is φ = 59018300.

The previous prime is 64920227. The next prime is 64920259. The reversal of 64920251 is 15202946.

It is a happy number.

It is not a de Polignac number, because 64920251 - 2⁶ = 64920187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64920259) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 268145 + ... + 268386.

It is an arithmetic number, because the mean of its divisors is an integer number (11893126).

Almost surely, 2^64920251 is an apocalyptic number.

64920251 is a deficient number, since it is larger than the sum of its proper divisors (6438505).

64920251 is a wasteful number, since it uses less digits than its factorization.

64920251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 536553 (or 536542 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 64920251 is about 8057.3104073258. The cubic root of 64920251 is about 401.9080732520.

The spelling of 64920251 in words is "sixty-four million, nine hundred twenty thousand, two hundred fifty-one".