31302101221 has 4 divisors (see below), whose sum is σ = 31302466092. Its totient is φ = 31301736352.

The previous prime is 31302101189. The next prime is 31302101227. The reversal of 31302101221 is 12210120313.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 29150440225 + 2151660996 = 170735^2 + 46386^2 .

It is a cyclic number.

It is not a de Polignac number, because 31302101221 - 2⁵ = 31302101189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31302101195 and 31302101204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31302101227) 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, 24465 + ... + 251401.

It is an arithmetic number, because the mean of its divisors is an integer number (7825616523).

Almost surely, 2^31302101221 is an apocalyptic number.

It is an amenable number.

31302101221 is a deficient number, since it is larger than the sum of its proper divisors (364871).

31302101221 is a wasteful number, since it uses less digits than its factorization.

31302101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364870.

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

Adding to 31302101221 its reverse (12210120313), we get a palindrome (43512221534).

The spelling of 31302101221 in words is "thirty-one billion, three hundred two million, one hundred one thousand, two hundred twenty-one".