21634197 has 24 divisors (see below), whose sum is σ = 31727808. Its totient is φ = 13104000.

The previous prime is 21634181. The next prime is 21634213. The reversal of 21634197 is 79143612.

It is an interprime number because it is at equal distance from previous prime (21634181) and next prime (21634213).

It is not a de Polignac number, because 21634197 - 2⁴ = 21634181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21634127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35697 + ... + 36297.

It is an arithmetic number, because the mean of its divisors is an integer number (1321992).

Almost surely, 2^21634197 is an apocalyptic number.

It is an amenable number.

21634197 is a deficient number, since it is larger than the sum of its proper divisors (10093611).

21634197 is a wasteful number, since it uses less digits than its factorization.

21634197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701 (or 688 counting only the distinct ones).

The product of its digits is 9072, while the sum is 33.

The square root of 21634197 is about 4651.2575718831. The cubic root of 21634197 is about 278.6422232769.

The spelling of 21634197 in words is "twenty-one million, six hundred thirty-four thousand, one hundred ninety-seven".