21554315244 has 192 divisors, whose sum is σ = 71154155520. Its totient is φ = 5479306560.

The previous prime is 21554315201. The next prime is 21554315261. The reversal of 21554315244 is 44251345512.

21554315244 is a `hidden beast` number, since 21 + 5 + 543 + 1 + 52 + 44 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21554315199 and 21554315208.

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, 363279 + ... + 418425.

It is an arithmetic number, because the mean of its divisors is an integer number (370594560).

Almost surely, 2^21554315244 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 21554315244, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35577077760).

21554315244 is an abundant number, since it is smaller than the sum of its proper divisors (49599840276).

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

21554315244 is a wasteful number, since it uses less digits than its factorization.

21554315244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55225 (or 55217 counting only the distinct ones).

The product of its digits is 96000, while the sum is 36.

The spelling of 21554315244 in words is "twenty-one billion, five hundred fifty-four million, three hundred fifteen thousand, two hundred forty-four".