31661670399 has 4 divisors (see below), whose sum is σ = 42215560536. Its totient is φ = 21107780264.

The previous prime is 31661670361. The next prime is 31661670401. The reversal of 31661670399 is 99307616613.

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

It is a cyclic number.

It is not a de Polignac number, because 31661670399 - 2⁹ = 31661669887 is a prime.

It is a super-2 number, since 2×31661670399² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31661620399) 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, 5276945064 + ... + 5276945069.

It is an arithmetic number, because the mean of its divisors is an integer number (10553890134).

Almost surely, 2^31661670399 is an apocalyptic number.

31661670399 is a deficient number, since it is larger than the sum of its proper divisors (10553890137).

31661670399 is a wasteful number, since it uses less digits than its factorization.

31661670399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10553890136.

The product of its (nonzero) digits is 1102248, while the sum is 51.

The spelling of 31661670399 in words is "thirty-one billion, six hundred sixty-one million, six hundred seventy thousand, three hundred ninety-nine".