21011031030 has 128 divisors (see below), whose sum is σ = 56358581760. Its totient is φ = 4970071040.

The previous prime is 21011031023. The next prime is 21011031043. The reversal of 21011031030 is 3013011012.

It is a junction number, because it is equal to n+sod(n) for n = 21011030997 and 21011031015.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2663452 + ... + 2671328.

It is an arithmetic number, because the mean of its divisors is an integer number (440301420).

Almost surely, 2^21011031030 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21011031030, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28179290880).

21011031030 is an abundant number, since it is smaller than the sum of its proper divisors (35347550730).

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

21011031030 is a wasteful number, since it uses less digits than its factorization.

21011031030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8094.

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

Adding to 21011031030 its reverse (3013011012), we get a palindrome (24024042042).

The spelling of 21011031030 in words is "twenty-one billion, eleven million, thirty-one thousand, thirty".