21746825 has 12 divisors (see below), whose sum is σ = 28552860. Its totient is φ = 16373760.

The previous prime is 21746821. The next prime is 21746843. The reversal of 21746825 is 52864712.

It can be written as a sum of positive squares in 6 ways, for example, as 1352569 + 20394256 = 1163^2 + 4516^2 .

It is not a de Polignac number, because 21746825 - 2² = 21746821 is a prime.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21746821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25160 + ... + 26009.

It is an arithmetic number, because the mean of its divisors is an integer number (2379405).

Almost surely, 2^21746825 is an apocalyptic number.

21746825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21746825 is a deficient number, since it is larger than the sum of its proper divisors (6806035).

21746825 is a wasteful number, since it uses less digits than its factorization.

21746825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51196 (or 51191 counting only the distinct ones).

The product of its digits is 26880, while the sum is 35.

The square root of 21746825 is about 4663.3491183912. The cubic root of 21746825 is about 279.1249253202.

The spelling of 21746825 in words is "twenty-one million, seven hundred forty-six thousand, eight hundred twenty-five".