31321989 has 6 divisors (see below), whose sum is σ = 45242886. Its totient is φ = 20881320.

The previous prime is 31321987. The next prime is 31322023. The reversal of 31321989 is 98912313.

It can be written as a sum of positive squares in only one way, i.e., 31169889 + 152100 = 5583^2 + 390^2 .

It is not a de Polignac number, because 31321989 - 2¹ = 31321987 is a prime.

It is a super-2 number, since 2×31321989² = 1962133989832242, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31321981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1740102 + ... + 1740119.

It is an arithmetic number, because the mean of its divisors is an integer number (7540481).

Almost surely, 2^31321989 is an apocalyptic number.

It is an amenable number.

31321989 is a deficient number, since it is larger than the sum of its proper divisors (13920897).

31321989 is a wasteful number, since it uses less digits than its factorization.

31321989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3480227 (or 3480224 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 31321989 is about 5596.6051316847. The cubic root of 31321989 is about 315.2219448688.

The spelling of 31321989 in words is "thirty-one million, three hundred twenty-one thousand, nine hundred eighty-nine".