31440172212 has 18 divisors (see below), whose sum is σ = 79473768738. Its totient is φ = 10480057392.

The previous prime is 31440172187. The next prime is 31440172213. The reversal of 31440172212 is 21227104413.

31440172212 is a `hidden beast` number, since 3 + 1 + 440 + 1 + 7 + 2 + 212 = 666.

It can be written as a sum of positive squares in only one way, i.e., 30966848676 + 473323536 = 175974^2 + 21756^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31440172213) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 436669023 + ... + 436669094.

Almost surely, 2^31440172212 is an apocalyptic number.

It is an amenable number.

31440172212 is an abundant number, since it is smaller than the sum of its proper divisors (48033596526).

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

31440172212 is a wasteful number, since it uses less digits than its factorization.

31440172212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873338127 (or 873338122 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

Adding to 31440172212 its reverse (21227104413), we get a palindrome (52667276625).

The spelling of 31440172212 in words is "thirty-one billion, four hundred forty million, one hundred seventy-two thousand, two hundred twelve".