311951989 has 4 divisors (see below), whose sum is σ = 330302124. Its totient is φ = 293601856.

The previous prime is 311951963. The next prime is 311951993. The reversal of 311951989 is 989159113.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 121925764 + 190026225 = 11042^2 + 13785^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-311951989 is a prime.

It is a super-2 number, since 2×311951989² = 194628086882112242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311951929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9175042 + ... + 9175075.

It is an arithmetic number, because the mean of its divisors is an integer number (82575531).

Almost surely, 2^311951989 is an apocalyptic number.

It is an amenable number.

311951989 is a deficient number, since it is larger than the sum of its proper divisors (18350135).

311951989 is a wasteful number, since it uses less digits than its factorization.

311951989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18350134.

The product of its digits is 87480, while the sum is 46.

The square root of 311951989 is about 17662.1626365516. The cubic root of 311951989 is about 678.2074971916.

The spelling of 311951989 in words is "three hundred eleven million, nine hundred fifty-one thousand, nine hundred eighty-nine".