1861129 has 4 divisors (see below), whose sum is σ = 1863940. Its totient is φ = 1858320.

The previous prime is 1861121. The next prime is 1861141. The reversal of 1861129 is 9211681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9211681 = 31 ⋅297151.

It can be written as a sum of positive squares in 2 ways, for example, as 273529 + 1587600 = 523^2 + 1260^2 .

It is a cyclic number.

It is not a de Polignac number, because 1861129 - 2³ = 1861121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1861097 and 1861106.

It is not an unprimeable number, because it can be changed into a prime (1861121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199 + ... + 1939.

It is an arithmetic number, because the mean of its divisors is an integer number (465985).

2^1861129 is an apocalyptic number.

It is an amenable number.

1861129 is a deficient number, since it is larger than the sum of its proper divisors (2811).

1861129 is a wasteful number, since it uses less digits than its factorization.

1861129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2810.

The product of its digits is 864, while the sum is 28.

The square root of 1861129 is about 1364.2320183898. The cubic root of 1861129 is about 123.0057723072.

The spelling of 1861129 in words is "one million, eight hundred sixty-one thousand, one hundred twenty-nine".