31002120220021 has 2 divisors, whose sum is σ = 31002120220022. Its totient is φ = 31002120220020.

The previous prime is 31002120219919. The next prime is 31002120220031. The reversal of 31002120220021 is 12002202120013.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28717155427921 + 2284964792100 = 5358839^2 + 1511610^2 .

It is a cyclic number.

It is not a de Polignac number, because 31002120220021 - 2⁹ = 31002120219509 is a prime.

It is a super-2 number, since 2×31002120220021² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31002120219977 and 31002120220004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31002120220031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15501060110010 + 15501060110011.

It is an arithmetic number, because the mean of its divisors is an integer number (15501060110011).

Almost surely, 2^{31002120220021} is an apocalyptic number.

It is an amenable number.

31002120220021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31002120220021 is an equidigital number, since it uses as much as digits as its factorization.

31002120220021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 31002120220021 its reverse (12002202120013), we get a palindrome (43004322340034).

The spelling of 31002120220021 in words is "thirty-one trillion, two billion, one hundred twenty million, two hundred twenty thousand, twenty-one".