21951651 has 8 divisors (see below), whose sum is σ = 29639680. Its totient is φ = 14449032.

The previous prime is 21951623. The next prime is 21951653. The reversal of 21951651 is 15615912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21951651 - 2¹⁴ = 21935267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21951653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46075 + ... + 46548.

It is an arithmetic number, because the mean of its divisors is an integer number (3704960).

Almost surely, 2^21951651 is an apocalyptic number.

21951651 is a deficient number, since it is larger than the sum of its proper divisors (7688029).

21951651 is an equidigital number, since it uses as much as digits as its factorization.

21951651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92705.

The product of its digits is 2700, while the sum is 30.

The square root of 21951651 is about 4685.2589042656. The cubic root of 21951651 is about 279.9985161486.

The spelling of 21951651 in words is "twenty-one million, nine hundred fifty-one thousand, six hundred fifty-one".