1819899774 has 144 divisors (see below), whose sum is σ = 5019356160. Its totient is φ = 466408800.

The previous prime is 1819899751. The next prime is 1819899779. The reversal of 1819899774 is 4779989181.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1819899779) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1203679 + ... + 1205189.

It is an arithmetic number, because the mean of its divisors is an integer number (34856640).

Almost surely, 2^1819899774 is an apocalyptic number.

1819899774 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1819899774, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2509678080).

1819899774 is an abundant number, since it is smaller than the sum of its proper divisors (3199456386).

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

1819899774 is a wasteful number, since it uses less digits than its factorization.

1819899774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1627 (or 1613 counting only the distinct ones).

The product of its digits is 9144576, while the sum is 63.

The square root of 1819899774 is about 42660.2833323924. The cubic root of 1819899774 is about 1220.9067374590.

The spelling of 1819899774 in words is "one billion, eight hundred nineteen million, eight hundred ninety-nine thousand, seven hundred seventy-four".