21631043345123 has 32 divisors (see below), whose sum is σ = 23072553072000. Its totient is φ = 20208853057536.

The previous prime is 21631043345117. The next prime is 21631043345159. The reversal of 21631043345123 is 32154334013612.

It is not a de Polignac number, because 21631043345123 - 2³⁶ = 21562323868387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21631043345623) 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, 3884185283 + ... + 3884190851.

It is an arithmetic number, because the mean of its divisors is an integer number (721017283500).

Almost surely, 2^{21631043345123} is an apocalyptic number.

21631043345123 is a deficient number, since it is larger than the sum of its proper divisors (1441509726877).

21631043345123 is a wasteful number, since it uses less digits than its factorization.

21631043345123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8271.

The product of its (nonzero) digits is 155520, while the sum is 38.

Adding to 21631043345123 its reverse (32154334013612), we get a palindrome (53785377358735).

The spelling of 21631043345123 in words is "twenty-one trillion, six hundred thirty-one billion, forty-three million, three hundred forty-five thousand, one hundred twenty-three".