19782018 has 48 divisors (see below), whose sum is σ = 44553600. Its totient is φ = 6339168.

The previous prime is 19782017. The next prime is 19782019. The reversal of 19782018 is 81028791.

It is an interprime number because it is at equal distance from previous prime (19782017) and next prime (19782019).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19782011) 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, 56508 + ... + 56856.

It is an arithmetic number, because the mean of its divisors is an integer number (928200).

Almost surely, 2^19782018 is an apocalyptic number.

19782018 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

19782018 is an abundant number, since it is smaller than the sum of its proper divisors (24771582).

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

19782018 is a wasteful number, since it uses less digits than its factorization.

19782018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471 (or 468 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 19782018 is about 4447.6980562983. The cubic root of 19782018 is about 270.4520000976.

It can be divided in two parts, 197 and 82018, that added together give a triangular number (82215 = T₄₀₅).

The spelling of 19782018 in words is "nineteen million, seven hundred eighty-two thousand, eighteen".