21506622 has 32 divisors (see below), whose sum is σ = 45450240. Its totient is φ = 6773760.

The previous prime is 21506609. The next prime is 21506627. The reversal of 21506622 is 22660512.

It is a junction number, because it is equal to n+sod(n) for n = 21506592 and 21506601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21506627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6654 + ... + 9342.

It is an arithmetic number, because the mean of its divisors is an integer number (1420320).

Almost surely, 2^21506622 is an apocalyptic number.

21506622 is an abundant number, since it is smaller than the sum of its proper divisors (23943618).

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

21506622 is a wasteful number, since it uses less digits than its factorization.

21506622 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2768.

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

The square root of 21506622 is about 4637.5232613972. The cubic root of 21506622 is about 278.0934333908.

The spelling of 21506622 in words is "twenty-one million, five hundred six thousand, six hundred twenty-two".