19866790944 has 1440 divisors, whose sum is σ = 85709352960. Its totient is φ = 4367001600.

The previous prime is 19866790921. The next prime is 19866790967. The reversal of 19866790944 is 44909766891.

It is an interprime number because it is at equal distance from previous prime (19866790921) and next prime (19866790967).

It is a super-2 number, since 2×19866790944² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 640864209 + ... + 640864239.

It is an arithmetic number, because the mean of its divisors is an integer number (59520384).

Almost surely, 2^19866790944 is an apocalyptic number.

19866790944 is a gapful number since it is divisible by the number (14) 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 19866790944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42854676480).

19866790944 is an abundant number, since it is smaller than the sum of its proper divisors (65842562016).

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

19866790944 is a wasteful number, since it uses less digits than its factorization.

19866790944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 23514624, while the sum is 63.

The spelling of 19866790944 in words is "nineteen billion, eight hundred sixty-six million, seven hundred ninety thousand, nine hundred forty-four".