21411645 has 16 divisors (see below), whose sum is σ = 34406592. Its totient is φ = 11370240.

The previous prime is 21411623. The next prime is 21411661. The reversal of 21411645 is 54611412.

It is a happy number.

It is not a de Polignac number, because 21411645 - 2⁶ = 21411581 is a prime.

It is a congruent number.

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, 654 + ... + 6576.

It is an arithmetic number, because the mean of its divisors is an integer number (2150412).

Almost surely, 2^21411645 is an apocalyptic number.

It is an amenable number.

21411645 is a deficient number, since it is larger than the sum of its proper divisors (12994947).

21411645 is a wasteful number, since it uses less digits than its factorization.

21411645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6172.

The product of its digits is 960, while the sum is 24.

The square root of 21411645 is about 4627.2718744418. The cubic root of 21411645 is about 277.6834595635.

The spelling of 21411645 in words is "twenty-one million, four hundred eleven thousand, six hundred forty-five".