20851842 has 16 divisors (see below), whose sum is σ = 45495072. Its totient is φ = 6318720.

The previous prime is 20851801. The next prime is 20851867. The reversal of 20851842 is 24815802.

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, 157903 + ... + 158034.

It is an arithmetic number, because the mean of its divisors is an integer number (2843442).

Almost surely, 2^20851842 is an apocalyptic number.

20851842 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

20851842 is an abundant number, since it is smaller than the sum of its proper divisors (24643230).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20851842 is a wasteful number, since it uses less digits than its factorization.

20851842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315953.

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 20851842 is about 4566.3817186039. The cubic root of 20851842 is about 275.2420656498.

The spelling of 20851842 in words is "twenty million, eight hundred fifty-one thousand, eight hundred forty-two".