21873125 has 20 divisors (see below), whose sum is σ = 27741120. Its totient is φ = 17238000.

The previous prime is 21873121. The next prime is 21873127. The reversal of 21873125 is 52137812.

It is not a de Polignac number, because 21873125 - 2² = 21873121 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21873121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 49154 + ... + 49596.

It is an arithmetic number, because the mean of its divisors is an integer number (1387056).

Almost surely, 2^21873125 is an apocalyptic number.

21873125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21873125 is a deficient number, since it is larger than the sum of its proper divisors (5867995).

21873125 is an frugal number, since it uses more digits than its factorization.

21873125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 542 (or 527 counting only the distinct ones).

The product of its digits is 3360, while the sum is 29.

The square root of 21873125 is about 4676.8712832405. The cubic root of 21873125 is about 279.6642446567.

The spelling of 21873125 in words is "twenty-one million, eight hundred seventy-three thousand, one hundred twenty-five".