21940653 has 16 divisors (see below), whose sum is σ = 34512896. Its totient is φ = 12132720.

The previous prime is 21940651. The next prime is 21940657. The reversal of 21940653 is 35604912.

It is not a de Polignac number, because 21940653 - 2¹ = 21940651 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 21940653.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21940651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16201 + ... + 17502.

It is an arithmetic number, because the mean of its divisors is an integer number (2157056).

Almost surely, 2^21940653 is an apocalyptic number.

It is an amenable number.

21940653 is a deficient number, since it is larger than the sum of its proper divisors (12572243).

21940653 is a wasteful number, since it uses less digits than its factorization.

21940653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33744.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 21940653 is about 4684.0850760848. The cubic root of 21940653 is about 279.9517476375.

The spelling of 21940653 in words is "twenty-one million, nine hundred forty thousand, six hundred fifty-three".