21886516 has 6 divisors (see below), whose sum is σ = 38301410. Its totient is φ = 10943256.

The previous prime is 21886511. The next prime is 21886517. The reversal of 21886516 is 61568812.

It can be written as a sum of positive squares in only one way, i.e., 20976400 + 910116 = 4580^2 + 954^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21886511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2735811 + ... + 2735818.

Almost surely, 2^21886516 is an apocalyptic number.

It is an amenable number.

21886516 is a deficient number, since it is larger than the sum of its proper divisors (16414894).

21886516 is a wasteful number, since it uses less digits than its factorization.

21886516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5471633 (or 5471631 counting only the distinct ones).

The product of its digits is 23040, while the sum is 37.

The square root of 21886516 is about 4678.3026836664. The cubic root of 21886516 is about 279.7213043273.

The spelling of 21886516 in words is "twenty-one million, eight hundred eighty-six thousand, five hundred sixteen".