161981210 has 32 divisors (see below), whose sum is σ = 297138240. Its totient is φ = 63562752.

The previous prime is 161981207. The next prime is 161981243. The reversal of 161981210 is 12189161.

161981210 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 280442 + ... + 281018.

It is an arithmetic number, because the mean of its divisors is an integer number (9285570).

Almost surely, 2^161981210 is an apocalyptic number.

161981210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161981210 is a deficient number, since it is larger than the sum of its proper divisors (135157030).

161981210 is a wasteful number, since it uses less digits than its factorization.

161981210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1070.

The product of its (nonzero) digits is 864, while the sum is 29.

The square root of 161981210 is about 12727.1838990407. The cubic root of 161981210 is about 545.1151006792.

The spelling of 161981210 in words is "one hundred sixty-one million, nine hundred eighty-one thousand, two hundred ten".