64255218634778 has 16 divisors (see below), whose sum is σ = 96414111176040. Its totient is φ = 32117183233536.

The previous prime is 64255218634643. The next prime is 64255218634807. The reversal of 64255218634778 is 87743681255246.

It can be written as a sum of positive squares in 4 ways, for example, as 31198893846409 + 33056324788369 = 5585597^2 + 5749463^2 .

It is a super-2 number, since 2×64255218634778² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78337208 + ... + 79153196.

Almost surely, 2^{64255218634778} is an apocalyptic number.

64255218634778 is a deficient number, since it is larger than the sum of its proper divisors (32158892541262).

64255218634778 is a wasteful number, since it uses less digits than its factorization.

64255218634778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 828721.

The product of its digits is 541900800, while the sum is 68.

The spelling of 64255218634778 in words is "sixty-four trillion, two hundred fifty-five billion, two hundred eighteen million, six hundred thirty-four thousand, seven hundred seventy-eight".