21413905 has 16 divisors (see below), whose sum is σ = 26417664. Its totient is φ = 16655680.

The previous prime is 21413891. The next prime is 21413939. The reversal of 21413905 is 50931412.

It is not a de Polignac number, because 21413905 - 2⁹ = 21413393 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21413905.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68700 + ... + 69010.

It is an arithmetic number, because the mean of its divisors is an integer number (1651104).

Almost surely, 2^21413905 is an apocalyptic number.

It is an amenable number.

21413905 is a deficient number, since it is larger than the sum of its proper divisors (5003759).

21413905 is a wasteful number, since it uses less digits than its factorization.

21413905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21413905 is about 4627.5160723654. The cubic root of 21413905 is about 277.6932290532.

The spelling of 21413905 in words is "twenty-one million, four hundred thirteen thousand, nine hundred five".