21450879 has 8 divisors (see below), whose sum is σ = 31779120. Its totient is φ = 14300568.

The previous prime is 21450859. The next prime is 21450887. The reversal of 21450879 is 97805412.

It is not a de Polignac number, because 21450879 - 2⁸ = 21450623 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21450809) 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, 397212 + ... + 397265.

It is an arithmetic number, because the mean of its divisors is an integer number (3972390).

Almost surely, 2^21450879 is an apocalyptic number.

21450879 is a deficient number, since it is larger than the sum of its proper divisors (10328241).

21450879 is an equidigital number, since it uses as much as digits as its factorization.

21450879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 794486 (or 794480 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 21450879 is about 4631.5093652070. The cubic root of 21450879 is about 277.8529621137.

The spelling of 21450879 in words is "twenty-one million, four hundred fifty thousand, eight hundred seventy-nine".