1861264404 has 18 divisors (see below), whose sum is σ = 4704862890. Its totient is φ = 620421456.

The previous prime is 1861264373. The next prime is 1861264409. The reversal of 1861264404 is 4044621681.

It is a happy number.

1861264404 is a `hidden beast` number, since 1 + 8 + 6 + 1 + 2 + 644 + 0 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1077152400 + 784112004 = 32820^2 + 28002^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 51701789 = 1861264404 / (1 + 8 + 6 + 1 + 2 + 6 + 4 + 4 + 0 + 4).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861264409) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25850859 + ... + 25850930.

Almost surely, 2^1861264404 is an apocalyptic number.

It is an amenable number.

1861264404 is an abundant number, since it is smaller than the sum of its proper divisors (2843598486).

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

1861264404 is a wasteful number, since it uses less digits than its factorization.

1861264404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51701799 (or 51701794 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 1861264404 is about 43142.3736481895. The cubic root of 1861264404 is about 1230.0875527604.

The spelling of 1861264404 in words is "one billion, eight hundred sixty-one million, two hundred sixty-four thousand, four hundred four".