21537373 has 8 divisors (see below), whose sum is σ = 25302816. Its totient is φ = 18073200.

The previous prime is 21537349. The next prime is 21537379. The reversal of 21537373 is 37373512.

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-21537373 is a prime.

It is a super-2 number, since 2×21537373² = 927716871482258, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21537379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75163 + ... + 75448.

It is an arithmetic number, because the mean of its divisors is an integer number (3162852).

Almost surely, 2^21537373 is an apocalyptic number.

It is an amenable number.

21537373 is a deficient number, since it is larger than the sum of its proper divisors (3765443).

21537373 is a wasteful number, since it uses less digits than its factorization.

21537373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150635.

The product of its digits is 13230, while the sum is 31.

The square root of 21537373 is about 4640.8375321702. The cubic root of 21537373 is about 278.2259131852.

The spelling of 21537373 in words is "twenty-one million, five hundred thirty-seven thousand, three hundred seventy-three".