21020244102 has 96 divisors (see below), whose sum is σ = 54107857440. Its totient is φ = 5813660160.

The previous prime is 21020244097. The next prime is 21020244109. The reversal of 21020244102 is 20144202012.

21020244102 is a `hidden beast` number, since 21 + 0 + 202 + 441 + 0 + 2 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020244109) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 183208 + ... + 274964.

It is an arithmetic number, because the mean of its divisors is an integer number (563623515).

Almost surely, 2^21020244102 is an apocalyptic number.

21020244102 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21020244102, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27053928720).

21020244102 is an abundant number, since it is smaller than the sum of its proper divisors (33087613338).

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

21020244102 is a wasteful number, since it uses less digits than its factorization.

21020244102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91878 (or 91875 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21020244102 its reverse (20144202012), we get a palindrome (41164446114).

The spelling of 21020244102 in words is "twenty-one billion, twenty million, two hundred forty-four thousand, one hundred two".