21164697 has 12 divisors (see below), whose sum is σ = 31028400. Its totient is φ = 13898808.

The previous prime is 21164687. The next prime is 21164713. The reversal of 21164697 is 79646112.

21164697 is a `hidden beast` number, since 2 + 1 + 1 + 646 + 9 + 7 = 666.

It is not a de Polignac number, because 21164697 - 2⁴ = 21164681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21164687) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16947 + ... + 18152.

It is an arithmetic number, because the mean of its divisors is an integer number (2585700).

Almost surely, 2^21164697 is an apocalyptic number.

It is an amenable number.

21164697 is a deficient number, since it is larger than the sum of its proper divisors (9863703).

21164697 is a wasteful number, since it uses less digits than its factorization.

21164697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35172 (or 35169 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 21164697 is about 4600.5105151494. The cubic root of 21164697 is about 276.6117887639.

The spelling of 21164697 in words is "twenty-one million, one hundred sixty-four thousand, six hundred ninety-seven".