21522651 has 8 divisors (see below), whose sum is σ = 28993104. Its totient is φ = 14200320.

The previous prime is 21522619. The next prime is 21522671. The reversal of 21522651 is 15622512.

It is a happy number.

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

It is not a de Polignac number, because 21522651 - 2⁵ = 21522619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21522601) 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, 36690 + ... + 37271.

It is an arithmetic number, because the mean of its divisors is an integer number (3624138).

Almost surely, 2^21522651 is an apocalyptic number.

21522651 is a deficient number, since it is larger than the sum of its proper divisors (7470453).

21522651 is an equidigital number, since it uses as much as digits as its factorization.

21522651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74061.

The product of its digits is 1200, while the sum is 24.

The square root of 21522651 is about 4639.2511249123. The cubic root of 21522651 is about 278.1625044067.

The spelling of 21522651 in words is "twenty-one million, five hundred twenty-two thousand, six hundred fifty-one".