21101524444 has 108 divisors (see below), whose sum is σ = 50849648472. Its totient is φ = 7588848960.

The previous prime is 21101524439. The next prime is 21101524459. The reversal of 21101524444 is 44442510112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 274087 + ... + 342529.

Almost surely, 2^21101524444 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21101524444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25424824236).

21101524444 is an abundant number, since it is smaller than the sum of its proper divisors (29748124028).

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

21101524444 is a wasteful number, since it uses less digits than its factorization.

21101524444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68496 (or 68476 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 28.

It can be divided in two parts, 2110152 and 4444, that added together give a triangular number (2114596 = T₂₀₅₆).

The spelling of 21101524444 in words is "twenty-one billion, one hundred one million, five hundred twenty-four thousand, four hundred forty-four".