165521830 has 16 divisors (see below), whose sum is σ = 300891024. Its totient is φ = 65552800.

The previous prime is 165521819. The next prime is 165521861. The reversal of 165521830 is 38125561.

It is a junction number, because it is equal to n+sod(n) for n = 165521792 and 165521801.

It is a congruent number.

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, 80932 + ... + 82951.

It is an arithmetic number, because the mean of its divisors is an integer number (18805689).

Almost surely, 2^165521830 is an apocalyptic number.

165521830 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

165521830 is a deficient number, since it is larger than the sum of its proper divisors (135369194).

165521830 is a wasteful number, since it uses less digits than its factorization.

165521830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163991.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 165521830 is about 12865.5287493363. The cubic root of 165521830 is about 549.0582561773.

The spelling of 165521830 in words is "one hundred sixty-five million, five hundred twenty-one thousand, eight hundred thirty".