21310375 has 8 divisors (see below), whose sum is σ = 26595504. Its totient is φ = 17048200.

The previous prime is 21310337. The next prime is 21310417. The reversal of 21310375 is 57301312.

It is a de Polignac number, because none of the positive numbers 2^k-21310375 is a prime.

It is a Duffinian number.

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 7 ways as a sum of consecutive naturals, for example, 85117 + ... + 85366.

It is an arithmetic number, because the mean of its divisors is an integer number (3324438).

Almost surely, 2^21310375 is an apocalyptic number.

21310375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21310375 is a deficient number, since it is larger than the sum of its proper divisors (5285129).

21310375 is an equidigital number, since it uses as much as digits as its factorization.

21310375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170498 (or 170488 counting only the distinct ones).

The product of its (nonzero) digits is 630, while the sum is 22.

The square root of 21310375 is about 4616.3161720142. The cubic root of 21310375 is about 277.2449839091.

Adding to 21310375 its reverse (57301312), we get a palindrome (78611687).

The spelling of 21310375 in words is "twenty-one million, three hundred ten thousand, three hundred seventy-five".