31087401973 has 2 divisors, whose sum is σ = 31087401974. Its totient is φ = 31087401972.

The previous prime is 31087401971. The next prime is 31087401977. The reversal of 31087401973 is 37910478013.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29411564004 + 1675837969 = 171498^2 + 40937^2 .

It is an emirp because it is prime and its reverse (37910478013) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31087401973 - 2¹ = 31087401971 is a prime.

It is a super-2 number, since 2×31087401973² (a number of 22 digits) contains 22 as substring.

Together with 31087401971, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31087401971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15543700986 + 15543700987.

It is an arithmetic number, because the mean of its divisors is an integer number (15543700987).

Almost surely, 2^31087401973 is an apocalyptic number.

It is an amenable number.

31087401973 is a deficient number, since it is larger than the sum of its proper divisors (1).

31087401973 is an equidigital number, since it uses as much as digits as its factorization.

31087401973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 127008, while the sum is 43.

Adding to 31087401973 its reverse (37910478013), we get a palindrome (68997879986).

The spelling of 31087401973 in words is "thirty-one billion, eighty-seven million, four hundred one thousand, nine hundred seventy-three".