1869840 has 180 divisors, whose sum is σ = 7442604. Its totient is φ = 419328.

The previous prime is 1869839. The next prime is 1869853. The reversal of 1869840 is 489681.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1016064 + 853776 = 1008^2 + 924^2 .

It is a tau number, because it is divible by the number of its divisors (180).

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

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 1869795 and 1869804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 35254 + ... + 35306.

2^1869840 is an apocalyptic number.

1869840 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 1869840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3721302).

1869840 is an abundant number, since it is smaller than the sum of its proper divisors (5572764).

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

1869840 is a wasteful number, since it uses less digits than its factorization.

1869840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 70 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 1869840 is about 1367.4209300724. The cubic root of 1869840 is about 123.1973828645.

The spelling of 1869840 in words is "one million, eight hundred sixty-nine thousand, eight hundred forty".