31890505305 has 16 divisors (see below), whose sum is σ = 51092769024. Its totient is φ = 16985616000.

The previous prime is 31890505303. The next prime is 31890505351. The reversal of 31890505305 is 50350509813.

It is a happy number.

It is not a de Polignac number, because 31890505305 - 2¹ = 31890505303 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31890505303) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1404204 + ... + 1426733.

It is an arithmetic number, because the mean of its divisors is an integer number (3193298064).

Almost surely, 2^31890505305 is an apocalyptic number.

It is an amenable number.

31890505305 is a deficient number, since it is larger than the sum of its proper divisors (19202263719).

31890505305 is a wasteful number, since it uses less digits than its factorization.

31890505305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2831696.

The product of its (nonzero) digits is 81000, while the sum is 39.

The spelling of 31890505305 in words is "thirty-one billion, eight hundred ninety million, five hundred five thousand, three hundred five".