163021661 has 16 divisors (see below), whose sum is σ = 181785600. Its totient is φ = 144942000.

The previous prime is 163021657. The next prime is 163021681. The reversal of 163021661 is 166120361.

It is a cyclic number.

It is not a de Polignac number, because 163021661 - 2² = 163021657 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 163021661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163021601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 154586 + ... + 155636.

It is an arithmetic number, because the mean of its divisors is an integer number (11361600).

Almost surely, 2^163021661 is an apocalyptic number.

163021661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

163021661 is a deficient number, since it is larger than the sum of its proper divisors (18763939).

163021661 is a wasteful number, since it uses less digits than its factorization.

163021661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1360.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 163021661 is about 12767.9936168530. The cubic root of 163021661 is about 546.2797532785.

The spelling of 163021661 in words is "one hundred sixty-three million, twenty-one thousand, six hundred sixty-one".