1818391320 has 48 divisors (see below), whose sum is σ = 5909772960. Its totient is φ = 484904256.

The previous prime is 1818391303. The next prime is 1818391327. The reversal of 1818391320 is 231938181.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1818391327) 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, 2525184 + ... + 2525903.

It is an arithmetic number, because the mean of its divisors is an integer number (123120270).

Almost surely, 2^1818391320 is an apocalyptic number.

1818391320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1818391320 is an abundant number, since it is smaller than the sum of its proper divisors (4091381640).

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

1818391320 is a wasteful number, since it uses less digits than its factorization.

1818391320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5051104 (or 5051097 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 1818391320 is about 42642.5998269336. The cubic root of 1818391320 is about 1220.5693213096.

The spelling of 1818391320 in words is "one billion, eight hundred eighteen million, three hundred ninety-one thousand, three hundred twenty".