31111002221 has 8 divisors (see below), whose sum is σ = 33505526040. Its totient is φ = 28716674112.

The previous prime is 31111002163. The next prime is 31111002281. The reversal of 31111002221 is 12220011113.

It can be written as a sum of positive squares in 4 ways, for example, as 130074025 + 30980928196 = 11405^2 + 176014^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31111002221 - 2²⁶ = 31043893357 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31111002196 and 31111002205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31111002281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 607031 + ... + 656283.

It is an arithmetic number, because the mean of its divisors is an integer number (4188190755).

Almost surely, 2^31111002221 is an apocalyptic number.

It is an amenable number.

31111002221 is a deficient number, since it is larger than the sum of its proper divisors (2394523819).

31111002221 is a wasteful number, since it uses less digits than its factorization.

31111002221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97855.

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

Adding to 31111002221 its reverse (12220011113), we get a palindrome (43331013334).

The spelling of 31111002221 in words is "thirty-one billion, one hundred eleven million, two thousand, two hundred twenty-one".