31561422066 has 80 divisors (see below), whose sum is σ = 74360265408. Its totient is φ = 9986090400.

The previous prime is 31561422023. The next prime is 31561422083. The reversal of 31561422066 is 66022416513.

31561422066 is a `hidden beast` number, since 3 + 15 + 614 + 2 + 20 + 6 + 6 = 666.

It is a super-2 number, since 2×31561422066² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31561422066.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 455776 + ... + 520436.

Almost surely, 2^31561422066 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31561422066, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37180132704).

31561422066 is an abundant number, since it is smaller than the sum of its proper divisors (42798843342).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31561422066 is a wasteful number, since it uses less digits than its factorization.

31561422066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64829 (or 64820 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

Adding to 31561422066 its reverse (66022416513), we get a palindrome (97583838579).

The spelling of 31561422066 in words is "thirty-one billion, five hundred sixty-one million, four hundred twenty-two thousand, sixty-six".