21972448 has 12 divisors (see below), whose sum is σ = 43258320. Its totient is φ = 10986208.

The previous prime is 21972439. The next prime is 21972451. The reversal of 21972448 is 84427912.

It is a super-2 number, since 2×21972448² = 965576942225408, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343288 + ... + 343351.

It is an arithmetic number, because the mean of its divisors is an integer number (3604860).

Almost surely, 2^21972448 is an apocalyptic number.

It is an amenable number.

21972448 is a deficient number, since it is larger than the sum of its proper divisors (21285872).

21972448 is an equidigital number, since it uses as much as digits as its factorization.

21972448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 686649 (or 686641 counting only the distinct ones).

The product of its digits is 32256, while the sum is 37.

The square root of 21972448 is about 4687.4777866140. The cubic root of 21972448 is about 280.0869117954.

The spelling of 21972448 in words is "twenty-one million, nine hundred seventy-two thousand, four hundred forty-eight".