161805640250 has 16 divisors (see below), whose sum is σ = 302900159016. Its totient is φ = 64722256000.

The previous prime is 161805640231. The next prime is 161805640279. The reversal of 161805640250 is 52046508161.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 41515285009 + 120290355241 = 203753^2 + 346829^2 .

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, 323611031 + ... + 323611530.

Almost surely, 2^161805640250 is an apocalyptic number.

161805640250 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161805640250 is a deficient number, since it is larger than the sum of its proper divisors (141094518766).

161805640250 is an equidigital number, since it uses as much as digits as its factorization.

161805640250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647222578 (or 647222568 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 38.

The spelling of 161805640250 in words is "one hundred sixty-one billion, eight hundred five million, six hundred forty thousand, two hundred fifty".