21992530 has 32 divisors (see below), whose sum is σ = 45486720. Its totient is φ = 7499520.

The previous prime is 21992521. The next prime is 21992533. The reversal of 21992530 is 3529912.

It is a junction number, because it is equal to n+sod(n) for n = 21992492 and 21992501.

It is not an unprimeable number, because it can be changed into a prime (21992533) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14026 + ... + 15514.

It is an arithmetic number, because the mean of its divisors is an integer number (1421460).

Almost surely, 2^21992530 is an apocalyptic number.

21992530 is an abundant number, since it is smaller than the sum of its proper divisors (23494190).

21992530 is a wasteful number, since it uses less digits than its factorization.

21992530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1714.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 21992530 is about 4689.6193875410. The cubic root of 21992530 is about 280.1722154848.

It can be divided in two parts, 21992 and 530, that added together give a palindrome (22522).

The spelling of 21992530 in words is "twenty-one million, nine hundred ninety-two thousand, five hundred thirty".