19665740053440 has 840 divisors, whose sum is σ = 78362103615840. Its totient is φ = 4673843306496.

The previous prime is 19665740053433. The next prime is 19665740053457. The reversal of 19665740053440 is 4435004756691.

It is a happy number.

19665740053440 is a `hidden beast` number, since 1 + 9 + 6 + 65 + 7 + 4 + 0 + 0 + 534 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 126956517 + ... + 127111323.

Almost surely, 2^{19665740053440} is an apocalyptic number.

19665740053440 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 19665740053440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39181051807920).

19665740053440 is an abundant number, since it is smaller than the sum of its proper divisors (58696363562400).

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

19665740053440 is a wasteful number, since it uses less digits than its factorization.

19665740053440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154891 (or 154859 counting only the distinct ones).

The product of its (nonzero) digits is 10886400, while the sum is 54.

The spelling of 19665740053440 in words is "nineteen trillion, six hundred sixty-five billion, seven hundred forty million, fifty-three thousand, four hundred forty".