21023725 has 12 divisors (see below), whose sum is σ = 27203616. Its totient is φ = 16087280.

The previous prime is 21023701. The next prime is 21023731. The reversal of 21023725 is 52732012.

It is not a de Polignac number, because 21023725 - 2⁹ = 21023213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21023696 and 21023705.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 17707 + ... + 18856.

It is an arithmetic number, because the mean of its divisors is an integer number (2266968).

Almost surely, 2^21023725 is an apocalyptic number.

21023725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21023725 is a deficient number, since it is larger than the sum of its proper divisors (6179891).

21023725 is a wasteful number, since it uses less digits than its factorization.

21023725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36596 (or 36591 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 21023725 is about 4585.1635739633. The cubic root of 21023725 is about 275.9962761172.

Adding to 21023725 its reverse (52732012), we get a palindrome (73755737).

The spelling of 21023725 in words is "twenty-one million, twenty-three thousand, seven hundred twenty-five".