161900290 has 16 divisors (see below), whose sum is σ = 300821760. Its totient is φ = 62670960.

The previous prime is 161900287. The next prime is 161900303. The reversal of 161900290 is 92009161.

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, 260820 + ... + 261439.

It is an arithmetic number, because the mean of its divisors is an integer number (18801360).

Almost surely, 2^161900290 is an apocalyptic number.

161900290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161900290 is a deficient number, since it is larger than the sum of its proper divisors (138921470).

161900290 is a wasteful number, since it uses less digits than its factorization.

161900290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522297.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 161900290 is about 12724.0044797226. The cubic root of 161900290 is about 545.0243122448.

The spelling of 161900290 in words is "one hundred sixty-one million, nine hundred thousand, two hundred ninety".