21512966 has 8 divisors (see below), whose sum is σ = 32343624. Its totient is φ = 10731760.

The previous prime is 21512957. The next prime is 21512969. The reversal of 21512966 is 66921512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21512966² = 925615412234312, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21512969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11255 + ... + 13026.

It is an arithmetic number, because the mean of its divisors is an integer number (4042953).

Almost surely, 2^21512966 is an apocalyptic number.

21512966 is a deficient number, since it is larger than the sum of its proper divisors (10830658).

21512966 is a wasteful number, since it uses less digits than its factorization.

21512966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24726.

The product of its digits is 6480, while the sum is 32.

The square root of 21512966 is about 4638.2071967518. The cubic root of 21512966 is about 278.1207746023.

The spelling of 21512966 in words is "twenty-one million, five hundred twelve thousand, nine hundred sixty-six".