31663616213 has 4 divisors (see below), whose sum is σ = 32261042988. Its totient is φ = 31066189440.

The previous prime is 31663616177. The next prime is 31663616221. The reversal of 31663616213 is 31261636613.

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 15817338289 + 15846277924 = 125767^2 + 125882^2 .

It is a cyclic number.

It is not a de Polignac number, because 31663616213 - 2¹⁰ = 31663615189 is a prime.

It is a super-2 number, since 2×31663616213² (a number of 22 digits) contains 22 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 (31663616293) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 298713308 + ... + 298713413.

It is an arithmetic number, because the mean of its divisors is an integer number (8065260747).

Almost surely, 2^31663616213 is an apocalyptic number.

It is an amenable number.

31663616213 is a deficient number, since it is larger than the sum of its proper divisors (597426775).

31663616213 is an equidigital number, since it uses as much as digits as its factorization.

31663616213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 597426774.

The product of its digits is 69984, while the sum is 38.

The spelling of 31663616213 in words is "thirty-one billion, six hundred sixty-three million, six hundred sixteen thousand, two hundred thirteen".