31213021201 has 4 divisors (see below), whose sum is σ = 31227964900. Its totient is φ = 31198077504.

The previous prime is 31213021157. The next prime is 31213021219. The reversal of 31213021201 is 10212031213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10212031213 = 19 ⋅537475327.

It can be written as a sum of positive squares in 2 ways, for example, as 22781374225 + 8431646976 = 150935^2 + 91824^2 .

It is a cyclic number.

It is not a de Polignac number, because 31213021201 - 2²⁹ = 30676150289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31213021261) 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, 7468716 + ... + 7472893.

It is an arithmetic number, because the mean of its divisors is an integer number (7806991225).

Almost surely, 2^31213021201 is an apocalyptic number.

It is an amenable number.

31213021201 is a deficient number, since it is larger than the sum of its proper divisors (14943699).

31213021201 is a wasteful number, since it uses less digits than its factorization.

31213021201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14943698.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 31213021201 its reverse (10212031213), we get a palindrome (41425052414).

The spelling of 31213021201 in words is "thirty-one billion, two hundred thirteen million, twenty-one thousand, two hundred one".