21031331022 has 80 divisors (see below), whose sum is σ = 50820406560. Its totient is φ = 6462307008.

The previous prime is 21031331017. The next prime is 21031331047. The reversal of 21031331022 is 22013313012.

21031331022 is a `hidden beast` number, since 21 + 0 + 313 + 310 + 22 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21031330986 and 21031331004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1621479 + ... + 1634397.

It is an arithmetic number, because the mean of its divisors is an integer number (635255082).

Almost surely, 2^21031331022 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21031331022, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25410203280).

21031331022 is an abundant number, since it is smaller than the sum of its proper divisors (29789075538).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21031331022 is a wasteful number, since it uses less digits than its factorization.

21031331022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13719 (or 13710 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21031331022 its reverse (22013313012), we get a palindrome (43044644034).

The spelling of 21031331022 in words is "twenty-one billion, thirty-one million, three hundred thirty-one thousand, twenty-two".