31401362561 has 2 divisors, whose sum is σ = 31401362562. Its totient is φ = 31401362560.

The previous prime is 31401362477. The next prime is 31401362563. The reversal of 31401362561 is 16526310413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16230760000 + 15170602561 = 127400^2 + 123169^2 .

It is an emirp because it is prime and its reverse (16526310413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31401362561 - 2¹⁴ = 31401346177 is a prime.

Together with 31401362563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31401362563) 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, 15700681280 + 15700681281.

It is an arithmetic number, because the mean of its divisors is an integer number (15700681281).

Almost surely, 2^31401362561 is an apocalyptic number.

It is an amenable number.

31401362561 is a deficient number, since it is larger than the sum of its proper divisors (1).

31401362561 is an equidigital number, since it uses as much as digits as its factorization.

31401362561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 32.

Adding to 31401362561 its reverse (16526310413), we get a palindrome (47927672974).

The spelling of 31401362561 in words is "thirty-one billion, four hundred one million, three hundred sixty-two thousand, five hundred sixty-one".