31100021243 has 4 divisors (see below), whose sum is σ = 31100431008. Its totient is φ = 31099611480.

The previous prime is 31100021203. The next prime is 31100021279. The reversal of 31100021243 is 34212000113.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 31100021243 - 2²² = 31095826939 is a prime.

It is a super-2 number, since 2×31100021243² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31100021203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53996 + ... + 255177.

It is an arithmetic number, because the mean of its divisors is an integer number (7775107752).

Almost surely, 2^31100021243 is an apocalyptic number.

31100021243 is a deficient number, since it is larger than the sum of its proper divisors (409765).

31100021243 is a wasteful number, since it uses less digits than its factorization.

31100021243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409764.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 31100021243 its reverse (34212000113), we get a palindrome (65312021356).

The spelling of 31100021243 in words is "thirty-one billion, one hundred million, twenty-one thousand, two hundred forty-three".