19717776400 has 405 divisors, whose sum is σ = 59547364599. Its totient is φ = 6254868480.

The previous prime is 19717776373. The next prime is 19717776437. The reversal of 19717776400 is 467771791.

It is a happy number.

The square root of 19717776400 is 140420.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 461218576 + 19256557824 = 21476^2 + 138768^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 334199571 + ... + 334199629.

Almost surely, 2^19717776400 is an apocalyptic number.

19717776400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19717776400 is the 140420-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19717776400

19717776400 is an abundant number, since it is smaller than the sum of its proper divisors (39829588199).

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

19717776400 is a wasteful number, since it uses less digits than its factorization.

19717776400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 518616, while the sum is 49.

Multiplying 19717776400 by its sum of digits (49), we get a square (966171043600 = 982940²).

19717776400 divided by its sum of digits (49) gives a square (402403600 = 20060²).

The spelling of 19717776400 in words is "nineteen billion, seven hundred seventeen million, seven hundred seventy-six thousand, four hundred".