64979691905 has 4 divisors (see below), whose sum is σ = 77975630292. Its totient is φ = 51983753520.

The previous prime is 64979691851. The next prime is 64979691929. The reversal of 64979691905 is 50919697946.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 23326147441 + 41653544464 = 152729^2 + 204092^2 .

It is not a de Polignac number, because 64979691905 - 2¹⁴ = 64979675521 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6497969186 + ... + 6497969195.

It is an arithmetic number, because the mean of its divisors is an integer number (19493907573).

Almost surely, 2^64979691905 is an apocalyptic number.

It is an amenable number.

64979691905 is a deficient number, since it is larger than the sum of its proper divisors (12995938387).

64979691905 is a wasteful number, since it uses less digits than its factorization.

64979691905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12995938386.

The product of its (nonzero) digits is 33067440, while the sum is 65.

The spelling of 64979691905 in words is "sixty-four billion, nine hundred seventy-nine million, six hundred ninety-one thousand, nine hundred five".