21426685 has 32 divisors (see below), whose sum is σ = 31426560. Its totient is φ = 13704768.

The previous prime is 21426683. The next prime is 21426697. The reversal of 21426685 is 58662412.

It is not a de Polignac number, because 21426685 - 2¹ = 21426683 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21426685.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21426683) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34306 + ... + 34924.

It is an arithmetic number, because the mean of its divisors is an integer number (982080).

Almost surely, 2^21426685 is an apocalyptic number.

It is an amenable number.

21426685 is a deficient number, since it is larger than the sum of its proper divisors (9999875).

21426685 is a wasteful number, since it uses less digits than its factorization.

21426685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 697.

The product of its digits is 23040, while the sum is 34.

The square root of 21426685 is about 4628.8967368046. The cubic root of 21426685 is about 277.7484612913.

The spelling of 21426685 in words is "twenty-one million, four hundred twenty-six thousand, six hundred eighty-five".