161878736 has 20 divisors (see below), whose sum is σ = 314948964. Its totient is φ = 80601600.

The previous prime is 161878721. The next prime is 161878747. The reversal of 161878736 is 637878161.

It can be written as a sum of positive squares in 2 ways, for example, as 51208336 + 110670400 = 7156^2 + 10520^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17135 + ... + 24846.

Almost surely, 2^161878736 is an apocalyptic number.

161878736 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

161878736 is a deficient number, since it is larger than the sum of its proper divisors (153070228).

161878736 is a wasteful number, since it uses less digits than its factorization.

161878736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42230 (or 42224 counting only the distinct ones).

The product of its digits is 338688, while the sum is 47.

The square root of 161878736 is about 12723.1574697478. The cubic root of 161878736 is about 545.0001245686. Note that the first 3 decimals are identical.

The spelling of 161878736 in words is "one hundred sixty-one million, eight hundred seventy-eight thousand, seven hundred thirty-six".