31449380581 has 2 divisors, whose sum is σ = 31449380582. Its totient is φ = 31449380580.

The previous prime is 31449380551. The next prime is 31449380593. The reversal of 31449380581 is 18508394413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29854656225 + 1594724356 = 172785^2 + 39934^2 .

It is a cyclic number.

It is not a de Polignac number, because 31449380581 - 2¹³ = 31449372389 is a prime.

It is a super-2 number, since 2×31449380581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31449380551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15724690290 + 15724690291.

It is an arithmetic number, because the mean of its divisors is an integer number (15724690291).

Almost surely, 2^31449380581 is an apocalyptic number.

It is an amenable number.

31449380581 is a deficient number, since it is larger than the sum of its proper divisors (1).

31449380581 is an equidigital number, since it uses as much as digits as its factorization.

31449380581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 414720, while the sum is 46.

The spelling of 31449380581 in words is "thirty-one billion, four hundred forty-nine million, three hundred eighty thousand, five hundred eighty-one".