20851628 has 12 divisors (see below), whose sum is σ = 41703312. Its totient is φ = 8936400.

The previous prime is 20851601. The next prime is 20851637. The reversal of 20851628 is 82615802.

20851628 is an admirable number.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 20851594 and 20851603.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 372323 + ... + 372378.

It is an arithmetic number, because the mean of its divisors is an integer number (3475276).

Almost surely, 2^20851628 is an apocalyptic number.

20851628 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20851628 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20851628 is a wasteful number, since it uses less digits than its factorization.

20851628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744712 (or 744710 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 20851628 is about 4566.3582864248. The cubic root of 20851628 is about 275.2411240543.

The spelling of 20851628 in words is "twenty million, eight hundred fifty-one thousand, six hundred twenty-eight".