1804117861 has 16 divisors (see below), whose sum is σ = 2316996864. Its totient is φ = 1365369984.

The previous prime is 1804117859. The next prime is 1804117937. The reversal of 1804117861 is 1687114081.

It is a cyclic number.

It is not a de Polignac number, because 1804117861 - 2¹ = 1804117859 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1804117861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1804117801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 428896 + ... + 433081.

It is an arithmetic number, because the mean of its divisors is an integer number (144812304).

Almost surely, 2^1804117861 is an apocalyptic number.

It is an amenable number.

1804117861 is a deficient number, since it is larger than the sum of its proper divisors (512879003).

1804117861 is a wasteful number, since it uses less digits than its factorization.

1804117861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 862020.

The product of its (nonzero) digits is 10752, while the sum is 37.

The square root of 1804117861 is about 42474.9086049635. The cubic root of 1804117861 is about 1217.3673097679.

The spelling of 1804117861 in words is "one billion, eight hundred four million, one hundred seventeen thousand, eight hundred sixty-one".