20851375 has 16 divisors (see below), whose sum is σ = 26866944. Its totient is φ = 16140000.

The previous prime is 20851361. The next prime is 20851399. The reversal of 20851375 is 57315802.

It is not a de Polignac number, because 20851375 - 2²³ = 12462767 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1185 + ... + 6565.

It is an arithmetic number, because the mean of its divisors is an integer number (1679184).

Almost surely, 2^20851375 is an apocalyptic number.

20851375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20851375 is a deficient number, since it is larger than the sum of its proper divisors (6015569).

20851375 is an equidigital number, since it uses as much as digits as its factorization.

20851375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5427 (or 5417 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 20851375 is about 4566.3305837401. The cubic root of 20851375 is about 275.2400108512.

The spelling of 20851375 in words is "twenty million, eight hundred fifty-one thousand, three hundred seventy-five".