1861641 has 12 divisors (see below), whose sum is σ = 2711280.
Its totient is φ = 1230840.
The previous prime is 1861637. The next prime is 1861649. The reversal of 1861641 is 1461681.
1861641 is a `hidden beast` number, since 1 + 8 + 616 + 41 = 666.
It is not a de Polignac number, because 1861641 - 22 = 1861637 is a prime.
It is a Curzon number.
It is not an unprimeable number, because it can be changed into a prime (1861649) by changing a digit.
It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 390 + ... + 1968.
It is an arithmetic number, because the mean of its divisors is an integer number (225940).
21861641 is an apocalyptic number.
It is an amenable number.
1861641 is a deficient number, since it is larger than the sum of its proper divisors (849639).
1861641 is a wasteful number, since it uses less digits than its factorization.
1861641 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1716 (or 1713 counting only the distinct ones).
The product of its digits is 1152, while the sum is 27.
The square root of 1861641 is about 1364.4196568505.
The cubic root of 1861641 is about 123.0170509774.
The spelling of 1861641 in words is "one million, eight hundred sixty-one thousand, six hundred forty-one".