21239373 has 8 divisors (see below), whose sum is σ = 29550528. Its totient is φ = 13543904.

The previous prime is 21239363. The next prime is 21239381. The reversal of 21239373 is 37393212.

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

It is a cyclic number.

It is not a de Polignac number, because 21239373 - 2⁴ = 21239357 is a prime.

It is a super-2 number, since 2×21239373² = 902221930866258, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21239373.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21239303) 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, 153840 + ... + 153977.

It is an arithmetic number, because the mean of its divisors is an integer number (3693816).

Almost surely, 2^21239373 is an apocalyptic number.

21239373 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21239373 is a deficient number, since it is larger than the sum of its proper divisors (8311155).

21239373 is a wasteful number, since it uses less digits than its factorization.

21239373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307843.

The product of its digits is 6804, while the sum is 30.

The square root of 21239373 is about 4608.6194245132. The cubic root of 21239373 is about 276.9367326303.

It can be divided in two parts, 21239 and 373, that added together give a palindrome (21612).

The spelling of 21239373 in words is "twenty-one million, two hundred thirty-nine thousand, three hundred seventy-three".