31023120213221 has 4 divisors (see below), whose sum is σ = 31112011675500. Its totient is φ = 30934228750944.

The previous prime is 31023120213179. The next prime is 31023120213227. The reversal of 31023120213221 is 12231202132013.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9952826136100 + 21070294077121 = 3154810^2 + 4590239^2 .

It is a cyclic number.

It is not a de Polignac number, because 31023120213221 - 2⁶ = 31023120213157 is a prime.

It is a super-2 number, since 2×31023120213221² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31023120213227) 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, 44445730616 + ... + 44445731313.

It is an arithmetic number, because the mean of its divisors is an integer number (7778002918875).

Almost surely, 2^{31023120213221} is an apocalyptic number.

It is an amenable number.

31023120213221 is a deficient number, since it is larger than the sum of its proper divisors (88891462279).

31023120213221 is an equidigital number, since it uses as much as digits as its factorization.

31023120213221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88891462278.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 31023120213221 its reverse (12231202132013), we get a palindrome (43254322345234).

The spelling of 31023120213221 in words is "thirty-one trillion, twenty-three billion, one hundred twenty million, two hundred thirteen thousand, two hundred twenty-one".