19649377440 has 768 divisors, whose sum is σ = 90284544000. Its totient is φ = 3866849280.

The previous prime is 19649377439. The next prime is 19649377441. The reversal of 19649377440 is 4477394691.

19649377440 is a `hidden beast` number, since 1 + 96 + 49 + 3 + 77 + 440 = 666.

It is an interprime number because it is at equal distance from previous prime (19649377439) and next prime (19649377441).

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

It is not an unprimeable number, because it can be changed into a prime (19649377441) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 6318606 + ... + 6321714.

It is an arithmetic number, because the mean of its divisors is an integer number (117558000).

Almost surely, 2^19649377440 is an apocalyptic number.

19649377440 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 19649377440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45142272000).

19649377440 is an abundant number, since it is smaller than the sum of its proper divisors (70635166560).

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

19649377440 is a wasteful number, since it uses less digits than its factorization.

19649377440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3170 (or 3156 counting only the distinct ones).

The product of its (nonzero) digits is 4572288, while the sum is 54.

The spelling of 19649377440 in words is "nineteen billion, six hundred forty-nine million, three hundred seventy-seven thousand, four hundred forty".