20891130 has 128 divisors (see below), whose sum is σ = 60092928. Its totient is φ = 4595712.

The previous prime is 20891093. The next prime is 20891131. The reversal of 20891130 is 3119802.

It is a self number, because there is not a number n which added to its sum of digits gives 20891130.

It is not an unprimeable number, because it can be changed into a prime (20891131) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 152422 + ... + 152558.

It is an arithmetic number, because the mean of its divisors is an integer number (469476).

Almost surely, 2^20891130 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20891130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30046464).

20891130 is an abundant number, since it is smaller than the sum of its proper divisors (39201798).

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

20891130 is a wasteful number, since it uses less digits than its factorization.

20891130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 20891130 is about 4570.6815684316. The cubic root of 20891130 is about 275.4148229826.

The spelling of 20891130 in words is "twenty million, eight hundred ninety-one thousand, one hundred thirty".