21861240474216 has 256 divisors, whose sum is σ = 66674927450880. Its totient is φ = 5884157952000.

The previous prime is 21861240474179. The next prime is 21861240474317. The reversal of 21861240474216 is 61247404216812.

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, 9207856 + ... + 11336096.

It is an arithmetic number, because the mean of its divisors is an integer number (260448935355).

Almost surely, 2^{21861240474216} is an apocalyptic number.

21861240474216 is a gapful number since it is divisible by the number (26) 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 21861240474216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33337463725440).

21861240474216 is an abundant number, since it is smaller than the sum of its proper divisors (44813686976664).

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

21861240474216 is a wasteful number, since it uses less digits than its factorization.

21861240474216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2128388 (or 2128384 counting only the distinct ones).

The product of its (nonzero) digits is 1032192, while the sum is 48.

The spelling of 21861240474216 in words is "twenty-one trillion, eight hundred sixty-one billion, two hundred forty million, four hundred seventy-four thousand, two hundred sixteen".