21316824 has 32 divisors (see below), whose sum is σ = 59214000. Its totient is φ = 7105536.

The previous prime is 21316819. The next prime is 21316831. The reversal of 21316824 is 42861312.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49129 + ... + 49560.

Almost surely, 2^21316824 is an apocalyptic number.

21316824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21316824 is an abundant number, since it is smaller than the sum of its proper divisors (37897176).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21316824 is a wasteful number, since it uses less digits than its factorization.

21316824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98704 (or 98694 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 21316824 is about 4617.0146198599. The cubic root of 21316824 is about 277.2729479496.

The spelling of 21316824 in words is "twenty-one million, three hundred sixteen thousand, eight hundred twenty-four".