78213721556136 has 64 divisors (see below), whose sum is σ = 196535574000000. Its totient is φ = 25937762754816.

The previous prime is 78213721556063. The next prime is 78213721556141. The reversal of 78213721556136 is 63165512731287.

It is a happy number.

It is a super-2 number, since 2×78213721556136² (a number of 29 digits) contains 22 as substring.

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, 49799790 + ... + 51346338.

It is an arithmetic number, because the mean of its divisors is an integer number (3070868343750).

Almost surely, 2^{78213721556136} is an apocalyptic number.

It is an amenable number.

78213721556136 is an abundant number, since it is smaller than the sum of its proper divisors (118321852443864).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78213721556136 is a wasteful number, since it uses less digits than its factorization.

78213721556136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1557346 (or 1557342 counting only the distinct ones).

The product of its digits is 12700800, while the sum is 57.

The spelling of 78213721556136 in words is "seventy-eight trillion, two hundred thirteen billion, seven hundred twenty-one million, five hundred fifty-six thousand, one hundred thirty-six".