31127987977 has 2 divisors, whose sum is σ = 31127987978. Its totient is φ = 31127987976.

The previous prime is 31127987873. The next prime is 31127988007. The reversal of 31127987977 is 77978972113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25917458121 + 5210529856 = 160989^2 + 72184^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31127987977 is a prime.

It is not a weakly prime, because it can be changed into another prime (31127987777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15563993988 + 15563993989.

It is an arithmetic number, because the mean of its divisors is an integer number (15563993989).

Almost surely, 2^31127987977 is an apocalyptic number.

It is an amenable number.

31127987977 is a deficient number, since it is larger than the sum of its proper divisors (1).

31127987977 is an equidigital number, since it uses as much as digits as its factorization.

31127987977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9335088, while the sum is 61.

The spelling of 31127987977 in words is "thirty-one billion, one hundred twenty-seven million, nine hundred eighty-seven thousand, nine hundred seventy-seven".