21169964 has 12 divisors (see below), whose sum is σ = 39226824. Its totient is φ = 9962304.

The previous prime is 21169963. The next prime is 21169969. The reversal of 21169964 is 46996112.

It is a super-2 number, since 2×21169964² = 896334751522592, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21169963) 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, 155594 + ... + 155729.

It is an arithmetic number, because the mean of its divisors is an integer number (3268902).

Almost surely, 2^21169964 is an apocalyptic number.

It is an amenable number.

21169964 is a deficient number, since it is larger than the sum of its proper divisors (18056860).

21169964 is a wasteful number, since it uses less digits than its factorization.

21169964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311344 (or 311342 counting only the distinct ones).

The product of its digits is 23328, while the sum is 38.

The square root of 21169964 is about 4601.0829160101. The cubic root of 21169964 is about 276.6347325281.

The spelling of 21169964 in words is "twenty-one million, one hundred sixty-nine thousand, nine hundred sixty-four".