19864819450 has 48 divisors (see below), whose sum is σ = 42614415360. Its totient is φ = 6748297920.

The previous prime is 19864819421. The next prime is 19864819463. The reversal of 19864819450 is 5491846891.

It is a super-2 number, since 2×19864819450² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19864819391 and 19864819400.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 222202 + ... + 298501.

It is an arithmetic number, because the mean of its divisors is an integer number (887800320).

Almost surely, 2^19864819450 is an apocalyptic number.

19864819450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19864819450 is an abundant number, since it is smaller than the sum of its proper divisors (22749595910).

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

19864819450 is a wasteful number, since it uses less digits than its factorization.

19864819450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520831 (or 520826 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 55.

The spelling of 19864819450 in words is "nineteen billion, eight hundred sixty-four million, eight hundred nineteen thousand, four hundred fifty".