165661210 has 128 divisors (see below), whose sum is σ = 375072768. Its totient is φ = 51840000.

The previous prime is 165661201. The next prime is 165661211. The reversal of 165661210 is 12166561.

It is not an unprimeable number, because it can be changed into a prime (165661211) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1640160 + ... + 1640260.

It is an arithmetic number, because the mean of its divisors is an integer number (2930256).

Almost surely, 2^165661210 is an apocalyptic number.

165661210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

165661210 is an abundant number, since it is smaller than the sum of its proper divisors (209411558).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165661210 is a wasteful number, since it uses less digits than its factorization.

165661210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 165661210 is about 12870.9444097937. The cubic root of 165661210 is about 549.2123270318.

The spelling of 165661210 in words is "one hundred sixty-five million, six hundred sixty-one thousand, two hundred ten".