19968390 has 64 divisors (see below), whose sum is σ = 57355200. Its totient is φ = 4914432.

The previous prime is 19968379. The next prime is 19968397. The reversal of 19968390 is 9386991.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19968397) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 666 + ... + 6354.

It is an arithmetic number, because the mean of its divisors is an integer number (896175).

Almost surely, 2^19968390 is an apocalyptic number.

19968390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19968390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28677600).

19968390 is an abundant number, since it is smaller than the sum of its proper divisors (37386810).

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

19968390 is a wasteful number, since it uses less digits than its factorization.

19968390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5718 (or 5712 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 19968390 is about 4468.6004520431. The cubic root of 19968390 is about 271.2986816856.

The spelling of 19968390 in words is "nineteen million, nine hundred sixty-eight thousand, three hundred ninety".