31005500381 has 2 divisors, whose sum is σ = 31005500382. Its totient is φ = 31005500380.

The previous prime is 31005500363. The next prime is 31005500429. The reversal of 31005500381 is 18300550013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26743369156 + 4262131225 = 163534^2 + 65285^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31005500381 is a prime.

It is a super-2 number, since 2×31005500381² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31005500381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31005500311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15502750190 + 15502750191.

It is an arithmetic number, because the mean of its divisors is an integer number (15502750191).

Almost surely, 2^31005500381 is an apocalyptic number.

It is an amenable number.

31005500381 is a deficient number, since it is larger than the sum of its proper divisors (1).

31005500381 is an equidigital number, since it uses as much as digits as its factorization.

31005500381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 26.

The spelling of 31005500381 in words is "thirty-one billion, five million, five hundred thousand, three hundred eighty-one".