21612897 has 24 divisors (see below), whose sum is σ = 32011200. Its totient is φ = 14048160.

The previous prime is 21612887. The next prime is 21612907. The reversal of 21612897 is 79821612.

It is an interprime number because it is at equal distance from previous prime (21612887) and next prime (21612907).

It is not a de Polignac number, because 21612897 - 2⁷ = 21612769 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21612827) 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, 95098 + ... + 95324.

It is an arithmetic number, because the mean of its divisors is an integer number (1333800).

Almost surely, 2^21612897 is an apocalyptic number.

It is an amenable number.

21612897 is a deficient number, since it is larger than the sum of its proper divisors (10398303).

21612897 is a wasteful number, since it uses less digits than its factorization.

21612897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453 (or 450 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21612897 is about 4648.9673046818. The cubic root of 21612897 is about 278.5507472953.

It can be divided in two parts, 216128 and 97, that added together give a square (216225 = 465²).

The spelling of 21612897 in words is "twenty-one million, six hundred twelve thousand, eight hundred ninety-seven".