19778940720 has 960 divisors, whose sum is σ = 90244224000. Its totient is φ = 3886755840.

The previous prime is 19778940707. The next prime is 19778940767. The reversal of 19778940720 is 2704987791.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 34760596 + ... + 34761164.

It is an arithmetic number, because the mean of its divisors is an integer number (94004400).

Almost surely, 2^19778940720 is an apocalyptic number.

19778940720 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 19778940720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45122112000).

19778940720 is an abundant number, since it is smaller than the sum of its proper divisors (70465283280).

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

19778940720 is a wasteful number, since it uses less digits than its factorization.

19778940720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639 (or 616 counting only the distinct ones).

The product of its (nonzero) digits is 1778112, while the sum is 54.

The spelling of 19778940720 in words is "nineteen billion, seven hundred seventy-eight million, nine hundred forty thousand, seven hundred twenty".