21612799 has 8 divisors (see below), whose sum is σ = 23502752. Its totient is φ = 19755360.

The previous prime is 21612769. The next prime is 21612827. The reversal of 21612799 is 99721612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21612799 - 2²³ = 13224191 is a prime.

It is a super-2 number, since 2×21612799² = 934226161228802, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21612749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6732 + ... + 9409.

It is an arithmetic number, because the mean of its divisors is an integer number (2937844).

Almost surely, 2^21612799 is an apocalyptic number.

21612799 is a deficient number, since it is larger than the sum of its proper divisors (1889953).

21612799 is a wasteful number, since it uses less digits than its factorization.

21612799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16257.

The product of its digits is 13608, while the sum is 37.

The square root of 21612799 is about 4648.9567646946. The cubic root of 21612799 is about 278.5503262810.

The spelling of 21612799 in words is "twenty-one million, six hundred twelve thousand, seven hundred ninety-nine".