21522090 has 32 divisors (see below), whose sum is σ = 52171776. Its totient is φ = 5681600.

The previous prime is 21522077. The next prime is 21522101. The reversal of 21522090 is 9022512.

It is an unprimeable number.

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, 522 + ... + 6581.

It is an arithmetic number, because the mean of its divisors is an integer number (1630368).

Almost surely, 2^21522090 is an apocalyptic number.

21522090 is an abundant number, since it is smaller than the sum of its proper divisors (30649686).

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

21522090 is a wasteful number, since it uses less digits than its factorization.

21522090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7214.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 21522090 is about 4639.1906621737. The cubic root of 21522090 is about 278.1600875650.

The spelling of 21522090 in words is "twenty-one million, five hundred twenty-two thousand, ninety".