20849904 has 30 divisors (see below), whose sum is σ = 58351176. Its totient is φ = 6949920.

The previous prime is 20849903. The next prime is 20849909. The reversal of 20849904 is 40994802.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20849903) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 72252 + ... + 72539.

Almost surely, 2^20849904 is an apocalyptic number.

20849904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20849904 is an abundant number, since it is smaller than the sum of its proper divisors (37501272).

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

20849904 is a wasteful number, since it uses less digits than its factorization.

20849904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144805 (or 144796 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 20849904 is about 4566.1695106511. The cubic root of 20849904 is about 275.2335382553.

The spelling of 20849904 in words is "twenty million, eight hundred forty-nine thousand, nine hundred four".