161551550 has 24 divisors (see below), whose sum is σ = 302162952. Its totient is φ = 64260000.

The previous prime is 161551543. The next prime is 161551567. The reversal of 161551550 is 55155161.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 125 + ... + 17975.

It is an arithmetic number, because the mean of its divisors is an integer number (12590123).

Almost surely, 2^161551550 is an apocalyptic number.

161551550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161551550 is a deficient number, since it is larger than the sum of its proper divisors (140611402).

161551550 is a wasteful number, since it uses less digits than its factorization.

161551550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18044 (or 18039 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 29.

The square root of 161551550 is about 12710.2930729390. The cubic root of 161551550 is about 544.6326958650.

The spelling of 161551550 in words is "one hundred sixty-one million, five hundred fifty-one thousand, five hundred fifty".