21985072 has 10 divisors (see below), whose sum is σ = 42596108. Its totient is φ = 10992528.

The previous prime is 21985069. The next prime is 21985081. The reversal of 21985072 is 27058912.

It is a plaindrome in base 11.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 687018 + ... + 687049.

Almost surely, 2^21985072 is an apocalyptic number.

It is an amenable number.

21985072 is a deficient number, since it is larger than the sum of its proper divisors (20611036).

21985072 is a wasteful number, since it uses less digits than its factorization.

21985072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1374075 (or 1374069 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 21985072 is about 4688.8241596375. The cubic root of 21985072 is about 280.1405416904.

The spelling of 21985072 in words is "twenty-one million, nine hundred eighty-five thousand, seventy-two".