78991763553 has 12 divisors (see below), whose sum is σ = 114203810448. Its totient is φ = 52612900440.

The previous prime is 78991763533. The next prime is 78991763597. The reversal of 78991763553 is 35536719987.

78991763553 is a `hidden beast` number, since 7 + 8 + 9 + 9 + 1 + 76 + 3 + 553 = 666.

It is not a de Polignac number, because 78991763553 - 2⁶ = 78991763489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78991763533) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4012575 + ... + 4032212.

It is an arithmetic number, because the mean of its divisors is an integer number (9516984204).

Almost surely, 2^78991763553 is an apocalyptic number.

It is an amenable number.

78991763553 is a deficient number, since it is larger than the sum of its proper divisors (35212046895).

78991763553 is a wasteful number, since it uses less digits than its factorization.

78991763553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8045884 (or 8045881 counting only the distinct ones).

The product of its digits is 42865200, while the sum is 63.

The spelling of 78991763553 in words is "seventy-eight billion, nine hundred ninety-one million, seven hundred sixty-three thousand, five hundred fifty-three".