19780140 has 48 divisors (see below), whose sum is σ = 58302720. Its totient is φ = 4996800.

The previous prime is 19780109. The next prime is 19780141. The reversal of 19780140 is 4108791.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 19780098 and 19780107.

It is not an unprimeable number, because it can be changed into a prime (19780141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7536 + ... + 9815.

It is an arithmetic number, because the mean of its divisors is an integer number (1214640).

Almost surely, 2^19780140 is an apocalyptic number.

19780140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19780140 is an abundant number, since it is smaller than the sum of its proper divisors (38522580).

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

19780140 is a wasteful number, since it uses less digits than its factorization.

19780140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17382 (or 17380 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 19780140 is about 4447.4869308408. The cubic root of 19780140 is about 270.4434414000.

The spelling of 19780140 in words is "nineteen million, seven hundred eighty thousand, one hundred forty".