21225963 has 16 divisors (see below), whose sum is σ = 30960000. Its totient is φ = 12828480.

The previous prime is 21225959. The next prime is 21225973. The reversal of 21225963 is 36952212.

It is not a de Polignac number, because 21225963 - 2² = 21225959 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21225963.

It is not an unprimeable number, because it can be changed into a prime (21225943) 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, 15823 + ... + 17111.

It is an arithmetic number, because the mean of its divisors is an integer number (1935000).

Almost surely, 2^21225963 is an apocalyptic number.

21225963 is a deficient number, since it is larger than the sum of its proper divisors (9734037).

21225963 is a wasteful number, since it uses less digits than its factorization.

21225963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1802.

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

The square root of 21225963 is about 4607.1643122424. The cubic root of 21225963 is about 276.8784367562.

The spelling of 21225963 in words is "twenty-one million, two hundred twenty-five thousand, nine hundred sixty-three".