31201321212 has 72 divisors (see below), whose sum is σ = 86389102800. Its totient is φ = 9451104768.

The previous prime is 31201321171. The next prime is 31201321267. The reversal of 31201321212 is 21212310213.

It is a super-2 number, since 2×31201321212² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 861262 + ... + 896757.

It is an arithmetic number, because the mean of its divisors is an integer number (1199848650).

Almost surely, 2^31201321212 is an apocalyptic number.

It is an amenable number.

31201321212 is an abundant number, since it is smaller than the sum of its proper divisors (55187781588).

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

31201321212 is a wasteful number, since it uses less digits than its factorization.

31201321212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1758075 (or 1758070 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 31201321212 its reverse (21212310213), we get a palindrome (52413631425).

The spelling of 31201321212 in words is "thirty-one billion, two hundred one million, three hundred twenty-one thousand, two hundred twelve".