21424959 has 8 divisors (see below), whose sum is σ = 31740720. Its totient is φ = 14283288.

The previous prime is 21424957. The next prime is 21424967. The reversal of 21424959 is 95942412.

It is not a de Polignac number, because 21424959 - 2¹ = 21424957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21424957) 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, 396732 + ... + 396785.

It is an arithmetic number, because the mean of its divisors is an integer number (3967590).

Almost surely, 2^21424959 is an apocalyptic number.

21424959 is a deficient number, since it is larger than the sum of its proper divisors (10315761).

21424959 is an equidigital number, since it uses as much as digits as its factorization.

21424959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793526 (or 793520 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 21424959 is about 4628.7102955359. The cubic root of 21424959 is about 277.7410031969.

The spelling of 21424959 in words is "twenty-one million, four hundred twenty-four thousand, nine hundred fifty-nine".