21632372 has 6 divisors (see below), whose sum is σ = 37856658. Its totient is φ = 10816184.

The previous prime is 21632339. The next prime is 21632399. The reversal of 21632372 is 27323612.

It can be written as a sum of positive squares in only one way, i.e., 21492496 + 139876 = 4636^2 + 374^2 .

It is a super-4 number, since 4×21632372⁴ (a number of 30 digits) contains 4444 as substring.

It is a congruent number.

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 as a sum of consecutive naturals, namely, 2704043 + ... + 2704050.

It is an arithmetic number, because the mean of its divisors is an integer number (6309443).

Almost surely, 2^21632372 is an apocalyptic number.

It is an amenable number.

21632372 is a deficient number, since it is larger than the sum of its proper divisors (16224286).

21632372 is a wasteful number, since it uses less digits than its factorization.

21632372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5408097 (or 5408095 counting only the distinct ones).

The product of its digits is 3024, while the sum is 26.

The square root of 21632372 is about 4651.0613842434. The cubic root of 21632372 is about 278.6343878986.

Adding to 21632372 its reverse (27323612), we get a palindrome (48955984).

The spelling of 21632372 in words is "twenty-one million, six hundred thirty-two thousand, three hundred seventy-two".