21164345 has 16 divisors (see below), whose sum is σ = 26429760. Its totient is φ = 16250304.

The previous prime is 21164327. The next prime is 21164357. The reversal of 21164345 is 54346112.

It is a cyclic number.

It is not a de Polignac number, because 21164345 - 2⁶ = 21164281 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32594 + ... + 33236.

It is an arithmetic number, because the mean of its divisors is an integer number (1651860).

Almost surely, 2^21164345 is an apocalyptic number.

It is an amenable number.

21164345 is a deficient number, since it is larger than the sum of its proper divisors (5265415).

21164345 is a wasteful number, since it uses less digits than its factorization.

21164345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904.

The product of its digits is 2880, while the sum is 26.

The square root of 21164345 is about 4600.4722583665. The cubic root of 21164345 is about 276.6102552686.

The spelling of 21164345 in words is "twenty-one million, one hundred sixty-four thousand, three hundred forty-five".