19983978 has 48 divisors (see below), whose sum is σ = 49795200. Its totient is φ = 5673888.

The previous prime is 19983973. The next prime is 19983983. The reversal of 19983978 is 87938991.

It is an interprime number because it is at equal distance from previous prime (19983973) and next prime (19983983).

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

Its product of digits (979776) is a multiple of the sum of its prime divisors (1008).

It is not an unprimeable number, because it can be changed into a prime (19983973) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 24676 + ... + 25472.

It is an arithmetic number, because the mean of its divisors is an integer number (1037400).

Almost surely, 2^19983978 is an apocalyptic number.

19983978 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 19983978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24897600).

19983978 is an abundant number, since it is smaller than the sum of its proper divisors (29811222).

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

19983978 is a wasteful number, since it uses less digits than its factorization.

19983978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1011 (or 1008 counting only the distinct ones).

The product of its digits is 979776, while the sum is 54.

The square root of 19983978 is about 4470.3442820436. The cubic root of 19983978 is about 271.3692582968.

The spelling of 19983978 in words is "nineteen million, nine hundred eighty-three thousand, nine hundred seventy-eight".