19900000 has 72 divisors (see below), whose sum is σ = 49215600. Its totient is φ = 7920000.

The previous prime is 19899989. The next prime is 19900009. The reversal of 19900000 is 991.

19900000 = 90³ + 91³ + ... + 109³.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19900009) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 99901 + ... + 100099.

It is an arithmetic number, because the mean of its divisors is an integer number (683550).

Almost surely, 2^19900000 is an apocalyptic number.

19900000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19900000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24607800).

19900000 is an abundant number, since it is smaller than the sum of its proper divisors (29315600).

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

19900000 is an frugal number, since it uses more digits than its factorization.

19900000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 81, while the sum is 19.

The square root of 19900000 is about 4460.9416046391. The cubic root of 19900000 is about 270.9886026170.

Adding to 19900000 its reverse (991), we get a palindrome (19900991).

The spelling of 19900000 in words is "nineteen million, nine hundred thousand".