21409713 has 24 divisors (see below), whose sum is σ = 35060480. Its totient is φ = 12480480.

The previous prime is 21409699. The next prime is 21409727. The reversal of 21409713 is 31790412.

It is an interprime number because it is at equal distance from previous prime (21409699) and next prime (21409727).

It is not a de Polignac number, because 21409713 - 2⁴ = 21409697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21409733) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2593 + ... + 7038.

Almost surely, 2^21409713 is an apocalyptic number.

It is an amenable number.

21409713 is a deficient number, since it is larger than the sum of its proper divisors (13650767).

21409713 is a wasteful number, since it uses less digits than its factorization.

21409713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9669 (or 9666 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21409713 is about 4627.0631074149. The cubic root of 21409713 is about 277.6751074015.

It can be divided in two parts, 21409 and 713, that added together give a palindrome (22122).

The spelling of 21409713 in words is "twenty-one million, four hundred nine thousand, seven hundred thirteen".