20891072 has 28 divisors (see below), whose sum is σ = 41605200. Its totient is φ = 10407936.

The previous prime is 20891071. The next prime is 20891081. The reversal of 20891072 is 27019802.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20891071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28373 + ... + 29099.

It is an arithmetic number, because the mean of its divisors is an integer number (1485900).

Almost surely, 2^20891072 is an apocalyptic number.

It is an amenable number.

20891072 is a deficient number, since it is larger than the sum of its proper divisors (20714128).

20891072 is an equidigital number, since it uses as much as digits as its factorization.

20891072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1188 (or 1178 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 20891072 is about 4570.6752236404. The cubic root of 20891072 is about 275.4145681045.

The spelling of 20891072 in words is "twenty million, eight hundred ninety-one thousand, seventy-two".