21412651 has 4 divisors (see below), whose sum is σ = 23059792. Its totient is φ = 19765512.

The previous prime is 21412649. The next prime is 21412663. The reversal of 21412651 is 15621412.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21412651 - 2¹ = 21412649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21412621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 823551 + ... + 823576.

It is an arithmetic number, because the mean of its divisors is an integer number (5764948).

Almost surely, 2^21412651 is an apocalyptic number.

21412651 is a deficient number, since it is larger than the sum of its proper divisors (1647141).

21412651 is a wasteful number, since it uses less digits than its factorization.

21412651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1647140.

The product of its digits is 480, while the sum is 22.

The square root of 21412651 is about 4627.3805765249. The cubic root of 21412651 is about 277.6878083682.

The spelling of 21412651 in words is "twenty-one million, four hundred twelve thousand, six hundred fifty-one".