161813550 has 24 divisors (see below), whose sum is σ = 401297976. Its totient is φ = 43150240.

The previous prime is 161813549. The next prime is 161813573. The reversal of 161813550 is 55318161.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 539229 + ... + 539528.

It is an arithmetic number, because the mean of its divisors is an integer number (16720749).

Almost surely, 2^161813550 is an apocalyptic number.

161813550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161813550 is an abundant number, since it is smaller than the sum of its proper divisors (239484426).

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

161813550 is a wasteful number, since it uses less digits than its factorization.

161813550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1078772 (or 1078767 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 161813550 is about 12720.5955049282. The cubic root of 161813550 is about 544.9269604444.

The spelling of 161813550 in words is "one hundred sixty-one million, eight hundred thirteen thousand, five hundred fifty".