31321220212121 has 16 divisors (see below), whose sum is σ = 36003048683904. Its totient is φ = 26691237792384.

The previous prime is 31321220212063. The next prime is 31321220212127. The reversal of 31321220212121 is 12121202212313.

It is a cyclic number.

It is not a de Polignac number, because 31321220212121 - 2³⁴ = 31304040342937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31321220212127) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 158865821 + ... + 159062853.

It is an arithmetic number, because the mean of its divisors is an integer number (2250190542744).

Almost surely, 2^{31321220212121} is an apocalyptic number.

It is an amenable number.

31321220212121 is a deficient number, since it is larger than the sum of its proper divisors (4681828471783).

31321220212121 is a wasteful number, since it uses less digits than its factorization.

31321220212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328480.

The product of its (nonzero) digits is 576, while the sum is 23.

Adding to 31321220212121 its reverse (12121202212313), we get a palindrome (43442422424434).

The spelling of 31321220212121 in words is "thirty-one trillion, three hundred twenty-one billion, two hundred twenty million, two hundred twelve thousand, one hundred twenty-one".