21102240624 has 80 divisors (see below), whose sum is σ = 58108557600. Its totient is φ = 6575841280.

The previous prime is 21102240619. The next prime is 21102240667. The reversal of 21102240624 is 42604220112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 21102240594 and 21102240603.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34804 + ... + 208364.

It is an arithmetic number, because the mean of its divisors is an integer number (726356970).

Almost surely, 2^21102240624 is an apocalyptic number.

21102240624 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21102240624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29054278800).

21102240624 is an abundant number, since it is smaller than the sum of its proper divisors (37006316976).

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

21102240624 is a wasteful number, since it uses less digits than its factorization.

21102240624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173738 (or 173732 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

Adding to 21102240624 its reverse (42604220112), we get a palindrome (63706460736).

It can be divided in two parts, 21102 and 240624, that added together give a triangular number (261726 = T₇₂₃).

The spelling of 21102240624 in words is "twenty-one billion, one hundred two million, two hundred forty thousand, six hundred twenty-four".