81177158196 has 36 divisors (see below), whose sum is σ = 205210168800. Its totient is φ = 27057423888.

The previous prime is 81177158149. The next prime is 81177158197. The reversal of 81177158196 is 69185177118.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81177158197) 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, 639465 + ... + 755823.

Almost surely, 2^81177158196 is an apocalyptic number.

It is an amenable number.

81177158196 is an abundant number, since it is smaller than the sum of its proper divisors (124033010604).

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

81177158196 is a wasteful number, since it uses less digits than its factorization.

81177158196 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135748 (or 135743 counting only the distinct ones).

The product of its digits is 846720, while the sum is 54.

The spelling of 81177158196 in words is "eighty-one billion, one hundred seventy-seven million, one hundred fifty-eight thousand, one hundred ninety-six".