31816147661 has 4 divisors (see below), whose sum is σ = 31976028000. Its totient is φ = 31656267324.

The previous prime is 31816147637. The next prime is 31816147681. The reversal of 31816147661 is 16674161813.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16674161813 = 29 ⋅574971097.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31816147661 is a prime.

It is a super-3 number, since 3×31816147661³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31816147681) 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, 79939871 + ... + 79940268.

It is an arithmetic number, because the mean of its divisors is an integer number (7994007000).

Almost surely, 2^31816147661 is an apocalyptic number.

It is an amenable number.

31816147661 is a deficient number, since it is larger than the sum of its proper divisors (159880339).

31816147661 is a wasteful number, since it uses less digits than its factorization.

31816147661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159880338.

The product of its digits is 145152, while the sum is 44.

The spelling of 31816147661 in words is "thirty-one billion, eight hundred sixteen million, one hundred forty-seven thousand, six hundred sixty-one".