20900891 has 8 divisors (see below), whose sum is σ = 22835568. Its totient is φ = 18972000.

The previous prime is 20900879. The next prime is 20900897. The reversal of 20900891 is 19800902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20900891 - 2⁶ = 20900827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20900897) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10301 + ... + 12161.

It is an arithmetic number, because the mean of its divisors is an integer number (2854446).

Almost surely, 2^20900891 is an apocalyptic number.

20900891 is a deficient number, since it is larger than the sum of its proper divisors (1934677).

20900891 is a wasteful number, since it uses less digits than its factorization.

20900891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2893.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 20900891 is about 4571.7492275933. The cubic root of 20900891 is about 275.4577104905.

The spelling of 20900891 in words is "twenty million, nine hundred thousand, eight hundred ninety-one".