1861440 has 112 divisors (see below), whose sum is σ = 6778752. Its totient is φ = 423936.

The previous prime is 1861417. The next prime is 1861469. The reversal of 1861440 is 441681.

1861440 = T₁₀₅ + T₁₀₆ + ... + T₂₃₀.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1861440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6582 + ... + 6858.

2^1861440 is an apocalyptic number.

1861440 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 1861440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3389376).

1861440 is an abundant number, since it is smaller than the sum of its proper divisors (4917312).

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

1861440 is a wasteful number, since it uses less digits than its factorization.

1861440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304 (or 294 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 1861440 is about 1364.3459971723. The cubic root of 1861440 is about 123.0126234648.

The spelling of 1861440 in words is "one million, eight hundred sixty-one thousand, four hundred forty".