1819323990 has 192 divisors, whose sum is σ = 5538274560. Its totient is φ = 425658240.

The previous prime is 1819323983. The next prime is 1819323991. The reversal of 1819323990 is 993239181.

It is a happy number.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1819323991) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 773997 + ... + 776343.

It is an arithmetic number, because the mean of its divisors is an integer number (28845180).

Almost surely, 2^1819323990 is an apocalyptic number.

1819323990 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 1819323990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2769137280).

1819323990 is an abundant number, since it is smaller than the sum of its proper divisors (3718950570).

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

1819323990 is a wasteful number, since it uses less digits than its factorization.

1819323990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2409 (or 2397 counting only the distinct ones).

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

The square root of 1819323990 is about 42653.5343201475. The cubic root of 1819323990 is about 1220.7779661342. Note that the first 3 decimals are identical.

The spelling of 1819323990 in words is "one billion, eight hundred nineteen million, three hundred twenty-three thousand, nine hundred ninety".