31289143 has 4 divisors (see below), whose sum is σ = 32935960. Its totient is φ = 29642328.

The previous prime is 31289123. The next prime is 31289147. The reversal of 31289143 is 34198213.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31289143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31289147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 823380 + ... + 823417.

It is an arithmetic number, because the mean of its divisors is an integer number (8233990).

Almost surely, 2^31289143 is an apocalyptic number.

31289143 is a deficient number, since it is larger than the sum of its proper divisors (1646817).

31289143 is a wasteful number, since it uses less digits than its factorization.

31289143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1646816.

The product of its digits is 5184, while the sum is 31.

The square root of 31289143 is about 5593.6699044545. The cubic root of 31289143 is about 315.1117198413. Note that the first 3 decimals are identical.

The spelling of 31289143 in words is "thirty-one million, two hundred eighty-nine thousand, one hundred forty-three".