21974272 has 18 divisors (see below), whose sum is σ = 43863218. Its totient is φ = 10987008.

The previous prime is 21974261. The next prime is 21974273. The reversal of 21974272 is 27247912.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21678336 + 295936 = 4656^2 + 544^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21974273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42663 + ... + 43174.

Almost surely, 2^21974272 is an apocalyptic number.

It is an amenable number.

21974272 is a deficient number, since it is larger than the sum of its proper divisors (21888946).

21974272 is an frugal number, since it uses more digits than its factorization.

21974272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85853 (or 85839 counting only the distinct ones).

The product of its digits is 14112, while the sum is 34.

The square root of 21974272 is about 4687.6723434984. The cubic root of 21974272 is about 280.0946618708.

The spelling of 21974272 in words is "twenty-one million, nine hundred seventy-four thousand, two hundred seventy-two".