1864918440 has 384 divisors, whose sum is σ = 7716384000. Its totient is φ = 387233280.

The previous prime is 1864918423. The next prime is 1864918441. The reversal of 1864918440 is 448194681.

1864918440 is a `hidden beast` number, since 1 + 86 + 491 + 84 + 4 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (1864918441) 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, 1357594 + ... + 1358966.

It is an arithmetic number, because the mean of its divisors is an integer number (20094750).

Almost surely, 2^1864918440 is an apocalyptic number.

1864918440 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 1864918440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3858192000).

1864918440 is an abundant number, since it is smaller than the sum of its proper divisors (5851465560).

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

1864918440 is a wasteful number, since it uses less digits than its factorization.

1864918440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1422 (or 1401 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The square root of 1864918440 is about 43184.7014578079. The cubic root of 1864918440 is about 1230.8919962357.

The spelling of 1864918440 in words is "one billion, eight hundred sixty-four million, nine hundred eighteen thousand, four hundred forty".