11989731 has 16 divisors (see below), whose sum is σ = 17811360. Its totient is φ = 7123200.

The previous prime is 11989727. The next prime is 11989763. The reversal of 11989731 is 13798911.

It is not a de Polignac number, because 11989731 - 2² = 11989727 is a prime.

It is a super-2 number, since 2×11989731² = 287507298904722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 11989731.

It is not an unprimeable number, because it can be changed into a prime (11989721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4170 + ... + 6431.

It is an arithmetic number, because the mean of its divisors is an integer number (1113210).

Almost surely, 2^11989731 is an apocalyptic number.

11989731 is a deficient number, since it is larger than the sum of its proper divisors (5821629).

11989731 is a wasteful number, since it uses less digits than its factorization.

11989731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10646.

The product of its digits is 13608, while the sum is 39.

The square root of 11989731 is about 3462.6190954247. The cubic root of 11989731 is about 228.8775239257.

It can be divided in two parts, 11989 and 731, that added together give a triangular number (12720 = T₁₅₉).

The spelling of 11989731 in words is "eleven million, nine hundred eighty-nine thousand, seven hundred thirty-one".