31881274897 has 2 divisors, whose sum is σ = 31881274898. Its totient is φ = 31881274896.

The previous prime is 31881274847. The next prime is 31881274933. The reversal of 31881274897 is 79847218813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27356829201 + 4524445696 = 165399^2 + 67264^2 .

It is an emirp because it is prime and its reverse (79847218813) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31881274897 - 2³¹ = 29733791249 is a prime.

It is not a weakly prime, because it can be changed into another prime (31881274837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15940637448 + 15940637449.

It is an arithmetic number, because the mean of its divisors is an integer number (15940637449).

Almost surely, 2^31881274897 is an apocalyptic number.

It is an amenable number.

31881274897 is a deficient number, since it is larger than the sum of its proper divisors (1).

31881274897 is an equidigital number, since it uses as much as digits as its factorization.

31881274897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5419008, while the sum is 58.

The spelling of 31881274897 in words is "thirty-one billion, eight hundred eighty-one million, two hundred seventy-four thousand, eight hundred ninety-seven".