21622506 has 16 divisors (see below), whose sum is σ = 43348800. Its totient is φ = 7190208.

The previous prime is 21622501. The next prime is 21622543. The reversal of 21622506 is 60522612.

It is not an unprimeable number, because it can be changed into a prime (21622501) 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, 1471 + ... + 6738.

It is an arithmetic number, because the mean of its divisors is an integer number (2709300).

Almost surely, 2^21622506 is an apocalyptic number.

21622506 is an abundant number, since it is smaller than the sum of its proper divisors (21726294).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21622506 is a wasteful number, since it uses less digits than its factorization.

21622506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8653.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 21622506 is about 4650.0006451612. Note that the first 3 decimals coincide. The cubic root of 21622506 is about 278.5920219960.

It can be divided in two parts, 216 and 22506, that added together give a palindrome (22722).

The spelling of 21622506 in words is "twenty-one million, six hundred twenty-two thousand, five hundred six".