31284945 has 48 divisors (see below), whose sum is σ = 57238272. Its totient is φ = 15776640.

The previous prime is 31284923. The next prime is 31284949. The reversal of 31284945 is 54948213.

It is not a de Polignac number, because 31284945 - 2⁸ = 31284689 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31284949) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 172755 + ... + 172935.

It is an arithmetic number, because the mean of its divisors is an integer number (1192464).

Almost surely, 2^31284945 is an apocalyptic number.

It is an amenable number.

31284945 is a deficient number, since it is larger than the sum of its proper divisors (25953327).

31284945 is a wasteful number, since it uses less digits than its factorization.

31284945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 382 (or 379 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 31284945 is about 5593.2946462707. The cubic root of 31284945 is about 315.0976265804.

It can be divided in two parts, 312 and 84945, that multiplied together give a triangular number (26502840 = T₇₂₈₀).

The spelling of 31284945 in words is "thirty-one million, two hundred eighty-four thousand, nine hundred forty-five".