64921925205 has 48 divisors (see below), whose sum is σ = 114754204656. Its totient is φ = 33942205440.

The previous prime is 64921925197. The next prime is 64921925207. The reversal of 64921925205 is 50252912946.

It can be written as a sum of positive squares in 8 ways, for example, as 17763025284 + 47158899921 = 133278^2 + 217161^2 .

It is not a de Polignac number, because 64921925205 - 2³ = 64921925197 is a prime.

It is a super-2 number, since 2×64921925205² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64921925207) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2881785 + ... + 2904225.

It is an arithmetic number, because the mean of its divisors is an integer number (2390712597).

Almost surely, 2^64921925205 is an apocalyptic number.

It is an amenable number.

64921925205 is a deficient number, since it is larger than the sum of its proper divisors (49832279451).

64921925205 is a wasteful number, since it uses less digits than its factorization.

64921925205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23718 (or 23715 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The spelling of 64921925205 in words is "sixty-four billion, nine hundred twenty-one million, nine hundred twenty-five thousand, two hundred five".