21522372 has 24 divisors (see below), whose sum is σ = 50928192. Its totient is φ = 7072800.

The previous prime is 21522367. The next prime is 21522373. The reversal of 21522372 is 27322512.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21522373) 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 7 ways as a sum of consecutive naturals, for example, 11779 + ... + 13482.

It is an arithmetic number, because the mean of its divisors is an integer number (2122008).

Almost surely, 2^21522372 is an apocalyptic number.

It is an amenable number.

21522372 is an abundant number, since it is smaller than the sum of its proper divisors (29405820).

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

21522372 is a wasteful number, since it uses less digits than its factorization.

21522372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25339 (or 25337 counting only the distinct ones).

The product of its digits is 1680, while the sum is 24.

The square root of 21522372 is about 4639.2210553066. The cubic root of 21522372 is about 278.1613024532.

Adding to 21522372 its reverse (27322512), we get a palindrome (48844884).

The spelling of 21522372 in words is "twenty-one million, five hundred twenty-two thousand, three hundred seventy-two".