1806499840 has 136 divisors (see below), whose sum is σ = 4482628200. Its totient is φ = 698351616.

The previous prime is 1806499831. The next prime is 1806499843. The reversal of 1806499840 is 489946081.

It can be written as a sum of positive squares in 4 ways, for example, as 191102976 + 1615396864 = 13824^2 + 40192^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1806499843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12124086 + ... + 12124234.

Almost surely, 2^1806499840 is an apocalyptic number.

1806499840 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 1806499840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2241314100).

1806499840 is an abundant number, since it is smaller than the sum of its proper divisors (2676128360).

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

1806499840 is an frugal number, since it uses more digits than its factorization.

1806499840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223 (or 193 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 49.

The square root of 1806499840 is about 42502.9391924841. The cubic root of 1806499840 is about 1217.9028379960.

The spelling of 1806499840 in words is "one billion, eight hundred six million, four hundred ninety-nine thousand, eight hundred forty".