31287640477 has 2 divisors, whose sum is σ = 31287640478. Its totient is φ = 31287640476.

The previous prime is 31287640471. The next prime is 31287640529. The reversal of 31287640477 is 77404678213.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28729911001 + 2557729476 = 169499^2 + 50574^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31287640477 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31287640477.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31287640471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15643820238 + 15643820239.

It is an arithmetic number, because the mean of its divisors is an integer number (15643820239).

Almost surely, 2^31287640477 is an apocalyptic number.

It is an amenable number.

31287640477 is a deficient number, since it is larger than the sum of its proper divisors (1).

31287640477 is an equidigital number, since it uses as much as digits as its factorization.

31287640477 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1580544, while the sum is 49.

It can be divided in two parts, 312876 and 40477, that added together give a palindrome (353353).

The spelling of 31287640477 in words is "thirty-one billion, two hundred eighty-seven million, six hundred forty thousand, four hundred seventy-seven".