31561626337861 has 4 divisors (see below), whose sum is σ = 31572910440172. Its totient is φ = 31550342235552.

The previous prime is 31561626337811. The next prime is 31561626337883. The reversal of 31561626337861 is 16873362616513.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21523976687236 + 10037649650625 = 4639394^2 + 3168225^2 .

It is a cyclic number.

It is not a de Polignac number, because 31561626337861 - 2⁷ = 31561626337733 is a prime.

It is a super-2 number, since 2×31561626337861² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31561626337796 and 31561626337805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31561626337811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5642046960 + ... + 5642052553.

It is an arithmetic number, because the mean of its divisors is an integer number (7893227610043).

Almost surely, 2^{31561626337861} is an apocalyptic number.

It is an amenable number.

31561626337861 is a deficient number, since it is larger than the sum of its proper divisors (11284102311).

31561626337861 is a wasteful number, since it uses less digits than its factorization.

31561626337861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11284102310.

The product of its digits is 19595520, while the sum is 58.

The spelling of 31561626337861 in words is "thirty-one trillion, five hundred sixty-one billion, six hundred twenty-six million, three hundred thirty-seven thousand, eight hundred sixty-one".