31781000086 has 32 divisors (see below), whose sum is σ = 52389058176. Its totient is φ = 14339688000.

The previous prime is 31781000071. The next prime is 31781000089. The reversal of 31781000086 is 68000018713.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31781000089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1687341 + ... + 1706071.

It is an arithmetic number, because the mean of its divisors is an integer number (1637158068).

Almost surely, 2^31781000086 is an apocalyptic number.

31781000086 is a deficient number, since it is larger than the sum of its proper divisors (20608058090).

31781000086 is a wasteful number, since it uses less digits than its factorization.

31781000086 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19308.

The product of its (nonzero) digits is 8064, while the sum is 34.

Adding to 31781000086 its reverse (68000018713), we get a palindrome (99781018799).

The spelling of 31781000086 in words is "thirty-one billion, seven hundred eighty-one million, eighty-six", and thus it is an aban number.