64874906781 has 4 divisors (see below), whose sum is σ = 86499875712. Its totient is φ = 43249937852.

The previous prime is 64874906773. The next prime is 64874906821. The reversal of 64874906781 is 18760947846.

64874906781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 64874906781 - 2³ = 64874906773 is a prime.

It is a super-2 number, since 2×64874906781² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64874906741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10812484461 + ... + 10812484466.

It is an arithmetic number, because the mean of its divisors is an integer number (21624968928).

Almost surely, 2^64874906781 is an apocalyptic number.

It is an amenable number.

64874906781 is a deficient number, since it is larger than the sum of its proper divisors (21624968931).

64874906781 is a wasteful number, since it uses less digits than its factorization.

64874906781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21624968930.

The product of its (nonzero) digits is 16257024, while the sum is 60.

The spelling of 64874906781 in words is "sixty-four billion, eight hundred seventy-four million, nine hundred six thousand, seven hundred eighty-one".