31128005 has 8 divisors (see below), whose sum is σ = 37548312. Its totient is φ = 24772608.

The previous prime is 31127983. The next prime is 31128011. The reversal of 31128005 is 50082113.

It can be written as a sum of positive squares in 4 ways, for example, as 114244 + 31013761 = 338^2 + 5569^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31128005 - 2¹⁴ = 31111621 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15164 + ... + 17093.

It is an arithmetic number, because the mean of its divisors is an integer number (4693539).

Almost surely, 2^31128005 is an apocalyptic number.

It is an amenable number.

31128005 is a deficient number, since it is larger than the sum of its proper divisors (6420307).

31128005 is a wasteful number, since it uses less digits than its factorization.

31128005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32455.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 31128005 is about 5579.2477091450. The cubic root of 31128005 is about 314.5698504326.

The spelling of 31128005 in words is "thirty-one million, one hundred twenty-eight thousand, five".