19791378 has 48 divisors (see below), whose sum is σ = 44911776. Its totient is φ = 6531840.

The previous prime is 19791377. The next prime is 19791379. The reversal of 19791378 is 87319791.

19791378 is a `hidden beast` number, since 197 + 91 + 378 = 666.

It is an interprime number because it is at equal distance from previous prime (19791377) and next prime (19791379).

It is not an unprimeable number, because it can be changed into a prime (19791377) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 93693 + ... + 93903.

It is an arithmetic number, because the mean of its divisors is an integer number (935662).

Almost surely, 2^19791378 is an apocalyptic number.

19791378 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19791378, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22455888).

19791378 is an abundant number, since it is smaller than the sum of its proper divisors (25120398).

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

19791378 is a wasteful number, since it uses less digits than its factorization.

19791378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421 (or 409 counting only the distinct ones).

The product of its digits is 95256, while the sum is 45.

The square root of 19791378 is about 4448.7501615622. The cubic root of 19791378 is about 270.4946487895.

The spelling of 19791378 in words is "nineteen million, seven hundred ninety-one thousand, three hundred seventy-eight".