1861291825 has 12 divisors (see below), whose sum is σ = 2342451760. Its totient is φ = 1466807760.

The previous prime is 1861291819. The next prime is 1861291843. The reversal of 1861291825 is 5281921681.

It is not a de Polignac number, because 1861291825 - 2²⁵ = 1827737393 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 553935 + ... + 557284.

Almost surely, 2^1861291825 is an apocalyptic number.

It is an amenable number.

1861291825 is a deficient number, since it is larger than the sum of its proper divisors (481159935).

1861291825 is a wasteful number, since it uses less digits than its factorization.

1861291825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1111296 (or 1111291 counting only the distinct ones).

The product of its digits is 69120, while the sum is 43.

The square root of 1861291825 is about 43142.6914436269. The cubic root of 1861291825 is about 1230.0935934686.

The spelling of 1861291825 in words is "one billion, eight hundred sixty-one million, two hundred ninety-one thousand, eight hundred twenty-five".