21374816 has 12 divisors (see below), whose sum is σ = 42081732. Its totient is φ = 10687392.

The previous prime is 21374813. The next prime is 21374819. The reversal of 21374816 is 61847312.

It is an interprime number because it is at equal distance from previous prime (21374813) and next prime (21374819).

It is a Harshad number since it is a multiple of its sum of digits (32), and also a Moran number because the ratio is a prime number: 667963 = 21374816 / (2 + 1 + 3 + 7 + 4 + 8 + 1 + 6).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21374813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333950 + ... + 334013.

It is an arithmetic number, because the mean of its divisors is an integer number (3506811).

Almost surely, 2^21374816 is an apocalyptic number.

It is an amenable number.

21374816 is a deficient number, since it is larger than the sum of its proper divisors (20706916).

21374816 is an equidigital number, since it uses as much as digits as its factorization.

21374816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667973 (or 667965 counting only the distinct ones).

The product of its digits is 8064, while the sum is 32.

The square root of 21374816 is about 4623.2906030229. The cubic root of 21374816 is about 277.5241588144.

The spelling of 21374816 in words is "twenty-one million, three hundred seventy-four thousand, eight hundred sixteen".