64642662515 has 16 divisors (see below), whose sum is σ = 77852569728. Its totient is φ = 51526803456.

The previous prime is 64642662479. The next prime is 64642662521. The reversal of 64642662515 is 51526624646.

It is a cyclic number.

It is not a de Polignac number, because 64642662515 - 2¹² = 64642658419 is a prime.

It is a super-2 number, since 2×64642662515² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64642662515.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2100479 + ... + 2131031.

It is an arithmetic number, because the mean of its divisors is an integer number (4865785608).

Almost surely, 2^64642662515 is an apocalyptic number.

64642662515 is a deficient number, since it is larger than the sum of its proper divisors (13209907213).

64642662515 is a wasteful number, since it uses less digits than its factorization.

64642662515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32078.

The product of its digits is 2073600, while the sum is 47.

The spelling of 64642662515 in words is "sixty-four billion, six hundred forty-two million, six hundred sixty-two thousand, five hundred fifteen".