19856052840 has 256 divisors, whose sum is σ = 65028096000. Its totient is φ = 4821341184.

The previous prime is 19856052829. The next prime is 19856052857. The reversal of 19856052840 is 4825065891.

It is a self number, because there is not a number n which added to its sum of digits gives 19856052840.

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, 51843289 + ... + 51843671.

It is an arithmetic number, because the mean of its divisors is an integer number (254016000).

Almost surely, 2^19856052840 is an apocalyptic number.

19856052840 is a gapful number since it is divisible by the number (10) 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 19856052840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32514048000).

19856052840 is an abundant number, since it is smaller than the sum of its proper divisors (45172043160).

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

19856052840 is a wasteful number, since it uses less digits than its factorization.

19856052840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776 (or 772 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 48.

The spelling of 19856052840 in words is "nineteen billion, eight hundred fifty-six million, fifty-two thousand, eight hundred forty".