21373716 has 144 divisors (see below), whose sum is σ = 65899904. Its totient is φ = 5246208.

The previous prime is 21373711. The next prime is 21373717. The reversal of 21373716 is 61737312.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21373711) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 577650 + ... + 577686.

Almost surely, 2^21373716 is an apocalyptic number.

21373716 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21373716, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32949952).

21373716 is an abundant number, since it is smaller than the sum of its proper divisors (44526188).

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

21373716 is a wasteful number, since it uses less digits than its factorization.

21373716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110 (or 85 counting only the distinct ones).

The product of its digits is 5292, while the sum is 30.

The square root of 21373716 is about 4623.1716386048. The cubic root of 21373716 is about 277.5193980434.

The spelling of 21373716 in words is "twenty-one million, three hundred seventy-three thousand, seven hundred sixteen".