21003031110 has 64 divisors (see below), whose sum is σ = 53140101120. Its totient is φ = 5298048000.

The previous prime is 21003031037. The next prime is 21003031117. The reversal of 21003031110 is 1113030012.

It is a super-2 number, since 2×21003031110² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003031117) 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, 356235 + ... + 410985.

It is an arithmetic number, because the mean of its divisors is an integer number (830314080).

Almost surely, 2^21003031110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21003031110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26570050560).

21003031110 is an abundant number, since it is smaller than the sum of its proper divisors (32137070010).

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

21003031110 is a wasteful number, since it uses less digits than its factorization.

21003031110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55453.

The product of its (nonzero) digits is 18, while the sum is 12.

Adding to 21003031110 its reverse (1113030012), we get a palindrome (22116061122).

The spelling of 21003031110 in words is "twenty-one billion, three million, thirty-one thousand, one hundred ten".