161550890 has 16 divisors (see below), whose sum is σ = 296279208. Its totient is φ = 63400896.

The previous prime is 161550877. The next prime is 161550911. The reversal of 161550890 is 98055161.

It can be written as a sum of positive squares in 4 ways, for example, as 126540001 + 35010889 = 11249^2 + 5917^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 161550890.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151877 + ... + 152936.

Almost surely, 2^161550890 is an apocalyptic number.

161550890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161550890 is a deficient number, since it is larger than the sum of its proper divisors (134728318).

161550890 is a wasteful number, since it uses less digits than its factorization.

161550890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304873.

The product of its (nonzero) digits is 10800, while the sum is 35.

The square root of 161550890 is about 12710.2671097031. The cubic root of 161550890 is about 544.6319541862.

The spelling of 161550890 in words is "one hundred sixty-one million, five hundred fifty thousand, eight hundred ninety".