20851258 has 8 divisors (see below), whose sum is σ = 31311252. Its totient is φ = 10414176.

The previous prime is 20851253. The next prime is 20851267. The reversal of 20851258 is 85215802.

It can be written as a sum of positive squares in 2 ways, for example, as 17114769 + 3736489 = 4137^2 + 1933^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (20851253) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3235 + ... + 7222.

Almost surely, 2^20851258 is an apocalyptic number.

20851258 is a deficient number, since it is larger than the sum of its proper divisors (10459994).

20851258 is a wasteful number, since it uses less digits than its factorization.

20851258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11456.

The product of its (nonzero) digits is 6400, while the sum is 31.

The square root of 20851258 is about 4566.3177725603. The cubic root of 20851258 is about 275.2394960468.

The spelling of 20851258 in words is "twenty million, eight hundred fifty-one thousand, two hundred fifty-eight".