21244434100 has 18 divisors (see below), whose sum is σ = 46100422214. Its totient is φ = 8497773600.

The previous prime is 21244434061. The next prime is 21244434151. The reversal of 21244434100 is 143444212.

It can be written as a sum of positive squares in 3 ways, for example, as 813162256 + 20431271844 = 28516^2 + 142938^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 106222071 + ... + 106222270.

Almost surely, 2^21244434100 is an apocalyptic number.

21244434100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21244434100 is an abundant number, since it is smaller than the sum of its proper divisors (24855988114).

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

21244434100 is a wasteful number, since it uses less digits than its factorization.

21244434100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212444355 (or 212444348 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21244434100 its reverse (143444212), we get a palindrome (21387878312).

The spelling of 21244434100 in words is "twenty-one billion, two hundred forty-four million, four hundred thirty-four thousand, one hundred".