21602725 has 12 divisors (see below), whose sum is σ = 26846496. Its totient is φ = 17244080.

The previous prime is 21602719. The next prime is 21602731. The reversal of 21602725 is 52720612.

It is an interprime number because it is at equal distance from previous prime (21602719) and next prime (21602731).

It is a de Polignac number, because none of the positive numbers 2^k-21602725 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21602725.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 17994 + ... + 19156.

It is an arithmetic number, because the mean of its divisors is an integer number (2237208).

Almost surely, 2^21602725 is an apocalyptic number.

21602725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21602725 is a deficient number, since it is larger than the sum of its proper divisors (5243771).

21602725 is a wasteful number, since it uses less digits than its factorization.

21602725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1916 (or 1911 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 21602725 is about 4647.8731695260. The cubic root of 21602725 is about 278.5070409406.

The spelling of 21602725 in words is "twenty-one million, six hundred two thousand, seven hundred twenty-five".