19550555640 has 576 divisors, whose sum is σ = 80762834880. Its totient is φ = 4014489600.

The previous prime is 19550555587. The next prime is 19550555683. The reversal of 19550555640 is 4655505591.

19550555640 is a `hidden beast` number, since 1 + 9 + 5 + 50 + 5 + 556 + 40 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 29576910 + ... + 29577570.

It is an arithmetic number, because the mean of its divisors is an integer number (140213255).

Almost surely, 2^19550555640 is an apocalyptic number.

19550555640 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 19550555640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40381417440).

19550555640 is an abundant number, since it is smaller than the sum of its proper divisors (61212279240).

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

19550555640 is a wasteful number, since it uses less digits than its factorization.

19550555640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 804 (or 786 counting only the distinct ones).

The product of its (nonzero) digits is 675000, while the sum is 45.

The spelling of 19550555640 in words is "nineteen billion, five hundred fifty million, five hundred fifty-five thousand, six hundred forty".