19000000 has 98 divisors (see below), whose sum is σ = 49608740. Its totient is φ = 7200000.

The previous prime is 18999997. The next prime is 19000013. The reversal of 19000000 is 91.

19000000 = 320² + 321² + ... + 447².

It is a happy number.

It is a super-2 number, since 2×19000000² = 722000000000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 999991 + ... + 1000009.

Almost surely, 2^19000000 is an apocalyptic number.

19000000 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 19000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24804370).

19000000 is an abundant number, since it is smaller than the sum of its proper divisors (30608740).

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

19000000 is an frugal number, since it uses more digits than its factorization.

19000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61 (or 26 counting only the distinct ones).

The product of its (nonzero) digits is 9, while the sum is 10.

The square root of 19000000 is about 4358.8989435407. The cubic root of 19000000 is about 266.8401648722.

Adding to 19000000 its reverse (91), we get a palindrome (19000091).

The spelling of 19000000 in words is "nineteen million", and thus it is an aban number and an uban number.