19309742640 has 120 divisors (see below), whose sum is σ = 65185024320. Its totient is φ = 5122547712.

The previous prime is 19309742633. The next prime is 19309742657. The reversal of 19309742640 is 4624790391.

It is a happy number.

19309742640 is a `hidden beast` number, since 19 + 309 + 74 + 264 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 69481 + ... + 208439.

It is an arithmetic number, because the mean of its divisors is an integer number (543208536).

Almost surely, 2^19309742640 is an apocalyptic number.

19309742640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a pronic number, being equal to 138959×138960.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19309742640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32592512160).

19309742640 is an abundant number, since it is smaller than the sum of its proper divisors (45875281680).

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

19309742640 is a wasteful number, since it uses less digits than its factorization.

19309742640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139171 (or 139162 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The spelling of 19309742640 in words is "nineteen billion, three hundred nine million, seven hundred forty-two thousand, six hundred forty".