21370651 has 6 divisors (see below), whose sum is σ = 22133852. Its totient is φ = 20632920.

The previous prime is 21370639. The next prime is 21370667. The reversal of 21370651 is 15607312.

It is not a de Polignac number, because 21370651 - 2⁵ = 21370619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21370621) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11865 + ... + 13546.

Almost surely, 2^21370651 is an apocalyptic number.

21370651 is a deficient number, since it is larger than the sum of its proper divisors (763201).

21370651 is an equidigital number, since it uses as much as digits as its factorization.

21370651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25469 (or 25440 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 21370651 is about 4622.8401443269. The cubic root of 21370651 is about 277.5061319425.

Adding to 21370651 its reverse (15607312), we get a palindrome (36977963).

The spelling of 21370651 in words is "twenty-one million, three hundred seventy thousand, six hundred fifty-one".