20857436 has 12 divisors (see below), whose sum is σ = 38647728. Its totient is φ = 9815232.

The previous prime is 20857429. The next prime is 20857469. The reversal of 20857436 is 63475802.

It is a happy number.

It is a hoax number, since the sum of its digits (35) 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 = 20857396 and 20857405.

It is a congruent number.

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, 153296 + ... + 153431.

It is an arithmetic number, because the mean of its divisors is an integer number (3220644).

Almost surely, 2^20857436 is an apocalyptic number.

It is an amenable number.

20857436 is a deficient number, since it is larger than the sum of its proper divisors (17790292).

20857436 is a wasteful number, since it uses less digits than its factorization.

20857436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306748 (or 306746 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 35.

The square root of 20857436 is about 4566.9941975001. The cubic root of 20857436 is about 275.2666768480.

The spelling of 20857436 in words is "twenty million, eight hundred fifty-seven thousand, four hundred thirty-six".