21342625 has 8 divisors (see below), whose sum is σ = 26635752. Its totient is φ = 17074000.

The previous prime is 21342583. The next prime is 21342631. The reversal of 21342625 is 52624312.

It can be written as a sum of positive squares in 4 ways, for example, as 4376464 + 16966161 = 2092^2 + 4119^2 .

It is not a de Polignac number, because 21342625 - 2¹³ = 21334433 is a prime.

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

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 21342625.

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 7 ways as a sum of consecutive naturals, for example, 85246 + ... + 85495.

It is an arithmetic number, because the mean of its divisors is an integer number (3329469).

Almost surely, 2^21342625 is an apocalyptic number.

21342625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21342625 is a deficient number, since it is larger than the sum of its proper divisors (5293127).

21342625 is an equidigital number, since it uses as much as digits as its factorization.

21342625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170756 (or 170746 counting only the distinct ones).

The product of its digits is 2880, while the sum is 25.

The square root of 21342625 is about 4619.8078964390. The cubic root of 21342625 is about 277.3847694073.

Adding to 21342625 its reverse (52624312), we get a palindrome (73966937).

The spelling of 21342625 in words is "twenty-one million, three hundred forty-two thousand, six hundred twenty-five".