19745994240 has 640 divisors, whose sum is σ = 82400440320. Its totient is φ = 4387405824.

The previous prime is 19745994223. The next prime is 19745994263. The reversal of 19745994240 is 4249954791.

19745994240 is a `hidden beast` number, since 1 + 9 + 7 + 4 + 599 + 4 + 2 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a super-2 number, since 2×19745994240² (a number of 21 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

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 63 ways as a sum of consecutive naturals, for example, 17901529 + ... + 17902631.

It is an arithmetic number, because the mean of its divisors is an integer number (128750688).

Almost surely, 2^19745994240 is an apocalyptic number.

19745994240 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 19745994240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41200220160).

19745994240 is an abundant number, since it is smaller than the sum of its proper divisors (62654446080).

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

19745994240 is a wasteful number, since it uses less digits than its factorization.

19745994240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1179 (or 1157 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 54.

The spelling of 19745994240 in words is "nineteen billion, seven hundred forty-five million, nine hundred ninety-four thousand, two hundred forty".