21887530 has 16 divisors (see below), whose sum is σ = 45025920. Its totient is φ = 7504272.

The previous prime is 21887507. The next prime is 21887533. The reversal of 21887530 is 3578812.

It is not an unprimeable number, because it can be changed into a prime (21887533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156270 + ... + 156409.

It is an arithmetic number, because the mean of its divisors is an integer number (2814120).

Almost surely, 2^21887530 is an apocalyptic number.

21887530 is an abundant number, since it is smaller than the sum of its proper divisors (23138390).

21887530 is a wasteful number, since it uses less digits than its factorization.

21887530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312693.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 21887530 is about 4678.4110550485. The cubic root of 21887530 is about 279.7256240802.

The spelling of 21887530 in words is "twenty-one million, eight hundred eighty-seven thousand, five hundred thirty".