31331220001221 has 32 divisors (see below), whose sum is σ = 48280271339520. Its totient is φ = 17702015354496.

The previous prime is 31331220001187. The next prime is 31331220001273. The reversal of 31331220001221 is 12210002213313.

It is not a de Polignac number, because 31331220001221 - 2¹⁹ = 31331219476933 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31331220021221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 104452560 + ... + 104752086.

It is an arithmetic number, because the mean of its divisors is an integer number (1508758479360).

Almost surely, 2^{31331220001221} is an apocalyptic number.

It is an amenable number.

31331220001221 is a deficient number, since it is larger than the sum of its proper divisors (16949051338299).

31331220001221 is a wasteful number, since it uses less digits than its factorization.

31331220001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355593.

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 31331220001221 its reverse (12210002213313), we get a palindrome (43541222214534).

The spelling of 31331220001221 in words is "thirty-one trillion, three hundred thirty-one billion, two hundred twenty million, one thousand, two hundred twenty-one".