161631693154 has 8 divisors (see below), whose sum is σ = 243052148268. Its totient is φ = 80614310400.

The previous prime is 161631693131. The next prime is 161631693247. The reversal of 161631693154 is 451396136161.

It can be written as a sum of positive squares in 2 ways, for example, as 145035297225 + 16596395929 = 380835^2 + 128827^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×161631693154² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100767087 + ... + 100768690.

Almost surely, 2^161631693154 is an apocalyptic number.

161631693154 is a deficient number, since it is larger than the sum of its proper divisors (81420455114).

161631693154 is a wasteful number, since it uses less digits than its factorization.

161631693154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201536180.

The product of its digits is 349920, while the sum is 46.

The spelling of 161631693154 in words is "one hundred sixty-one billion, six hundred thirty-one million, six hundred ninety-three thousand, one hundred fifty-four".