19891131 has 12 divisors (see below), whose sum is σ = 28719288. Its totient is φ = 12240384.

The previous prime is 19891127. The next prime is 19891133. The reversal of 19891131 is 13119891.

It is a happy number.

It is not a de Polignac number, because 19891131 - 2² = 19891127 is a prime.

It is a super-2 number, since 2×19891131² = 791314184918322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19891092 and 19891101.

It is not an unprimeable number, because it can be changed into a prime (19891133) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19110 + ... + 20123.

It is an arithmetic number, because the mean of its divisors is an integer number (2393274).

Almost surely, 2^19891131 is an apocalyptic number.

19891131 is a deficient number, since it is larger than the sum of its proper divisors (8828157).

19891131 is a wasteful number, since it uses less digits than its factorization.

19891131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39262 (or 39249 counting only the distinct ones).

The product of its digits is 1944, while the sum is 33.

The square root of 19891131 is about 4459.9474212147. The cubic root of 19891131 is about 270.9483387133.

The spelling of 19891131 in words is "nineteen million, eight hundred ninety-one thousand, one hundred thirty-one".