78155218537 has 24 divisors (see below), whose sum is σ = 87445657152. Its totient is φ = 69786874080.

The previous prime is 78155218529. The next prime is 78155218543. The reversal of 78155218537 is 73581255187.

It is not a de Polignac number, because 78155218537 - 2³ = 78155218529 is a prime.

It is a super-2 number, since 2×78155218537² (a number of 23 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (52) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78155218597) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1714948 + ... + 1759930.

It is an arithmetic number, because the mean of its divisors is an integer number (3643569048).

Almost surely, 2^78155218537 is an apocalyptic number.

It is an amenable number.

78155218537 is a deficient number, since it is larger than the sum of its proper divisors (9290438615).

78155218537 is a wasteful number, since it uses less digits than its factorization.

78155218537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45261 (or 45250 counting only the distinct ones).

The product of its digits is 2352000, while the sum is 52.

It can be divided in two parts, 78155 and 218537, that added together give a palindrome (296692).

The spelling of 78155218537 in words is "seventy-eight billion, one hundred fifty-five million, two hundred eighteen thousand, five hundred thirty-seven".