78564639525 has 36 divisors (see below), whose sum is σ = 132685334976. Its totient is φ = 41000940800.

The previous prime is 78564639487. The next prime is 78564639557. The reversal of 78564639525 is 52593646587.

It is not a de Polignac number, because 78564639525 - 2¹⁰ = 78564638501 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 16639165 + ... + 16643885.

Almost surely, 2^78564639525 is an apocalyptic number.

78564639525 is a gapful number since it is divisible by the number (75) formed by its first and last digit.

It is an amenable number.

78564639525 is a deficient number, since it is larger than the sum of its proper divisors (54120695451).

78564639525 is an frugal number, since it uses more digits than its factorization.

78564639525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9502 (or 4776 counting only the distinct ones).

The product of its digits is 54432000, while the sum is 60.

The spelling of 78564639525 in words is "seventy-eight billion, five hundred sixty-four million, six hundred thirty-nine thousand, five hundred twenty-five".