19840390 has 8 divisors (see below), whose sum is σ = 35712720. Its totient is φ = 7936152.

The previous prime is 19840369. The next prime is 19840397. The reversal of 19840390 is 9304891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19840397) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 992010 + ... + 992029.

It is an arithmetic number, because the mean of its divisors is an integer number (4464090).

Almost surely, 2^19840390 is an apocalyptic number.

19840390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19840390 is a deficient number, since it is larger than the sum of its proper divisors (15872330).

19840390 is a wasteful number, since it uses less digits than its factorization.

19840390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1984046.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 19840390 is about 4454.2552688412. The cubic root of 19840390 is about 270.7177519173.

The spelling of 19840390 in words is "nineteen million, eight hundred forty thousand, three hundred ninety".