19719507656640 has 448 divisors, whose sum is σ = 69219336775680. Its totient is φ = 4716460277760.

The previous prime is 19719507656609. The next prime is 19719507656657. The reversal of 19719507656640 is 4665670591791.

It is a Harshad number since it is a multiple of its sum of digits (66).

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, 435123262 + ... + 435168578.

It is an arithmetic number, because the mean of its divisors is an integer number (154507448160).

Almost surely, 2^{19719507656640} is an apocalyptic number.

19719507656640 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 19719507656640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34609668387840).

19719507656640 is an abundant number, since it is smaller than the sum of its proper divisors (49499829119040).

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

19719507656640 is a wasteful number, since it uses less digits than its factorization.

19719507656640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45900 (or 45890 counting only the distinct ones).

The product of its (nonzero) digits is 85730400, while the sum is 66.

The spelling of 19719507656640 in words is "nineteen trillion, seven hundred nineteen billion, five hundred seven million, six hundred fifty-six thousand, six hundred forty".