19689955740 has 384 divisors, whose sum is σ = 79365888000. Its totient is φ = 3935526912.

The previous prime is 19689955687. The next prime is 19689955741. The reversal of 19689955740 is 4755998691.

19689955740 is a `hidden beast` number, since 19 + 68 + 9 + 9 + 557 + 4 + 0 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19689955741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 923116 + ... + 944204.

It is an arithmetic number, because the mean of its divisors is an integer number (206682000).

Almost surely, 2^19689955740 is an apocalyptic number.

19689955740 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 19689955740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39682944000).

19689955740 is an abundant number, since it is smaller than the sum of its proper divisors (59675932260).

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

19689955740 is a wasteful number, since it uses less digits than its factorization.

19689955740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21146 (or 21138 counting only the distinct ones).

The product of its (nonzero) digits is 24494400, while the sum is 63.

The spelling of 19689955740 in words is "nineteen billion, six hundred eighty-nine million, nine hundred fifty-five thousand, seven hundred forty".