1861520 has 20 divisors (see below), whose sum is σ = 4328220. Its totient is φ = 744576.

The previous prime is 1861511. The next prime is 1861543. The reversal of 1861520 is 251681.

It can be written as a sum of positive squares in 2 ways, for example, as 712336 + 1149184 = 844^2 + 1072^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11555 + ... + 11714.

It is an arithmetic number, because the mean of its divisors is an integer number (216411).

2^1861520 is an apocalyptic number.

1861520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1861520 is an abundant number, since it is smaller than the sum of its proper divisors (2466700).

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

1861520 is a wasteful number, since it uses less digits than its factorization.

1861520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23282 (or 23276 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 1861520 is about 1364.3753149335. The cubic root of 1861520 is about 123.0143856971.

The spelling of 1861520 in words is "one million, eight hundred sixty-one thousand, five hundred twenty".