13891220 has 24 divisors (see below), whose sum is σ = 33339264. Its totient is φ = 4762656.

The previous prime is 13891217. The next prime is 13891231. The reversal of 13891220 is 2219831.

It is a self number, because there is not a number n which added to its sum of digits gives 13891220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49472 + ... + 49751.

It is an arithmetic number, because the mean of its divisors is an integer number (1389136).

Almost surely, 2^13891220 is an apocalyptic number.

13891220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13891220 is an abundant number, since it is smaller than the sum of its proper divisors (19448044).

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

13891220 is a wasteful number, since it uses less digits than its factorization.

13891220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99239 (or 99237 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 13891220 is about 3727.0927007522. The cubic root of 13891220 is about 240.3883758083.

The spelling of 13891220 in words is "thirteen million, eight hundred ninety-one thousand, two hundred twenty".