31191070216 has 8 divisors (see below), whose sum is σ = 58483256670. Its totient is φ = 15595535104.

The previous prime is 31191070199. The next prime is 31191070219. The reversal of 31191070216 is 61207019113.

It can be written as a sum of positive squares in only one way, i.e., 22095633316 + 9095436900 = 148646^2 + 95370^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×31191070216² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31191070219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1949441881 + ... + 1949441896.

Almost surely, 2^31191070216 is an apocalyptic number.

It is an amenable number.

31191070216 is a deficient number, since it is larger than the sum of its proper divisors (27292186454).

31191070216 is a wasteful number, since it uses less digits than its factorization.

31191070216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3898883783 (or 3898883779 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 31.

Adding to 31191070216 its reverse (61207019113), we get a palindrome (92398089329).

The spelling of 31191070216 in words is "thirty-one billion, one hundred ninety-one million, seventy thousand, two hundred sixteen".