21990512 has 10 divisors (see below), whose sum is σ = 42606648. Its totient is φ = 10995248.

The previous prime is 21990509. The next prime is 21990517. The reversal of 21990512 is 21509912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21990517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 687188 + ... + 687219.

Almost surely, 2^21990512 is an apocalyptic number.

It is an amenable number.

21990512 is a deficient number, since it is larger than the sum of its proper divisors (20616136).

21990512 is a wasteful number, since it uses less digits than its factorization.

21990512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1374415 (or 1374409 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 21990512 is about 4689.4042265516. The cubic root of 21990512 is about 280.1636458353.

The spelling of 21990512 in words is "twenty-one million, nine hundred ninety thousand, five hundred twelve".