31284143 has 4 divisors (see below), whose sum is σ = 34128168. Its totient is φ = 28440120.

The previous prime is 31284139. The next prime is 31284157. The reversal of 31284143 is 34148213.

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

It is a cyclic number.

It is not a de Polignac number, because 31284143 - 2² = 31284139 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 (31284133) 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, 1421996 + ... + 1422017.

It is an arithmetic number, because the mean of its divisors is an integer number (8532042).

Almost surely, 2^31284143 is an apocalyptic number.

31284143 is a deficient number, since it is larger than the sum of its proper divisors (2844025).

31284143 is a wasteful number, since it uses less digits than its factorization.

31284143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2844024.

The product of its digits is 2304, while the sum is 26.

The square root of 31284143 is about 5593.2229528242. Note that the first 3 decimals coincide. The cubic root of 31284143 is about 315.0949340131.

The spelling of 31284143 in words is "thirty-one million, two hundred eighty-four thousand, one hundred forty-three".