21612893 has 8 divisors (see below), whose sum is σ = 22603968. Its totient is φ = 20626144.

The previous prime is 21612887. The next prime is 21612907. The reversal of 21612893 is 39821612.

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 21612893 - 2⁸ = 21612637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21612883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13430 + ... + 14952.

It is an arithmetic number, because the mean of its divisors is an integer number (2825496).

Almost surely, 2^21612893 is an apocalyptic number.

21612893 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21612893 is a deficient number, since it is larger than the sum of its proper divisors (991075).

21612893 is a wasteful number, since it uses less digits than its factorization.

21612893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2163.

The product of its digits is 5184, while the sum is 32.

The square root of 21612893 is about 4648.9668744787. The cubic root of 21612893 is about 278.5507301111.

The spelling of 21612893 in words is "twenty-one million, six hundred twelve thousand, eight hundred ninety-three".