161378212500 has 108 divisors (see below), whose sum is σ = 509878045404. Its totient is φ = 43034160000.

The previous prime is 161378212481. The next prime is 161378212531. The reversal of 161378212500 is 5212873161.

161378212500 is a `hidden beast` number, since 1 + 6 + 137 + 8 + 2 + 12 + 500 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 153511941636 + 7866270864 = 391806^2 + 88692^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 604737 + ... + 829736.

It is an arithmetic number, because the mean of its divisors is an integer number (4721093013).

Almost surely, 2^161378212500 is an apocalyptic number.

161378212500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161378212500 is an abundant number, since it is smaller than the sum of its proper divisors (348499832904).

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

161378212500 is a wasteful number, since it uses less digits than its factorization.

161378212500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1434508 (or 1434483 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The spelling of 161378212500 in words is "one hundred sixty-one billion, three hundred seventy-eight million, two hundred twelve thousand, five hundred".