21373853 has 8 divisors (see below), whose sum is σ = 21732480. Its totient is φ = 21018240.

The previous prime is 21373843. The next prime is 21373867. The reversal of 21373853 is 35837312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21373853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21373813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16748 + ... + 17978.

It is an arithmetic number, because the mean of its divisors is an integer number (2716560).

Almost surely, 2^21373853 is an apocalyptic number.

It is an amenable number.

21373853 is a deficient number, since it is larger than the sum of its proper divisors (358627).

21373853 is a wasteful number, since it uses less digits than its factorization.

21373853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1507.

The product of its digits is 15120, while the sum is 32.

The square root of 21373853 is about 4623.1864552492. The cubic root of 21373853 is about 277.5199909847.

The spelling of 21373853 in words is "twenty-one million, three hundred seventy-three thousand, eight hundred fifty-three".