20891801946 has 16 divisors (see below), whose sum is σ = 41915417184. Its totient is φ = 6941965104.

The previous prime is 20891801941. The next prime is 20891801947. The reversal of 20891801946 is 64910819802.

It is a junction number, because it is equal to n+sod(n) for n = 20891801895 and 20891801904.

It is not an unprimeable number, because it can be changed into a prime (20891801941) 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, 5490160 + ... + 5493963.

It is an arithmetic number, because the mean of its divisors is an integer number (2619713574).

Almost surely, 2^20891801946 is an apocalyptic number.

20891801946 is an abundant number, since it is smaller than the sum of its proper divisors (21023615238).

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

20891801946 is a wasteful number, since it uses less digits than its factorization.

20891801946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10984445.

The product of its (nonzero) digits is 248832, while the sum is 48.

The spelling of 20891801946 in words is "twenty billion, eight hundred ninety-one million, eight hundred one thousand, nine hundred forty-six".