31220011121 has 16 divisors (see below), whose sum is σ = 34511155728. Its totient is φ = 28065312000.

The previous prime is 31220011111. The next prime is 31220011169. The reversal of 31220011121 is 12111002213.

It can be written as a sum of positive squares in 8 ways, for example, as 2156580721 + 29063430400 = 46439^2 + 170480^2 .

It is a cyclic number.

It is not a de Polignac number, because 31220011121 - 2¹⁰ = 31220010097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31220011096 and 31220011105.

It is not an unprimeable number, because it can be changed into a prime (31220011111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 114806 + ... + 274991.

It is an arithmetic number, because the mean of its divisors is an integer number (2156947233).

Almost surely, 2^31220011121 is an apocalyptic number.

It is an amenable number.

31220011121 is a deficient number, since it is larger than the sum of its proper divisors (3291144607).

31220011121 is a wasteful number, since it uses less digits than its factorization.

31220011121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389972.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 31220011121 its reverse (12111002213), we get a palindrome (43331013334).

The spelling of 31220011121 in words is "thirty-one billion, two hundred twenty million, eleven thousand, one hundred twenty-one".