21164045 has 16 divisors (see below), whose sum is σ = 29317248. Its totient is φ = 14366400.

The previous prime is 21164029. The next prime is 21164047. The reversal of 21164045 is 54046112.

It is not a de Polignac number, because 21164045 - 2⁴ = 21164029 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 21164045.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21164047) 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, 542 + ... + 6528.

It is an arithmetic number, because the mean of its divisors is an integer number (1832328).

Almost surely, 2^21164045 is an apocalyptic number.

It is an amenable number.

21164045 is a deficient number, since it is larger than the sum of its proper divisors (8153203).

21164045 is a wasteful number, since it uses less digits than its factorization.

21164045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6100.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21164045 is about 4600.4396529028. The cubic root of 21164045 is about 276.6089482989.

The spelling of 21164045 in words is "twenty-one million, one hundred sixty-four thousand, forty-five".