1864396809 has 24 divisors (see below), whose sum is σ = 2939537952. Its totient is φ = 1129283520.

The previous prime is 1864396801. The next prime is 1864396819. The reversal of 1864396809 is 9086934681.

It is not a de Polignac number, because 1864396809 - 2³ = 1864396801 is a prime.

It is a super-2 number, since 2×1864396809² = 6951950922818764962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1864396801) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 208774 + ... + 217520.

It is an arithmetic number, because the mean of its divisors is an integer number (122480748).

Almost surely, 2^1864396809 is an apocalyptic number.

It is an amenable number.

1864396809 is a deficient number, since it is larger than the sum of its proper divisors (1075141143).

1864396809 is a wasteful number, since it uses less digits than its factorization.

1864396809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10917 (or 10914 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 54.

The square root of 1864396809 is about 43178.6615007923. The cubic root of 1864396809 is about 1230.7772224414. Note that the first 3 decimals are identical.

The spelling of 1864396809 in words is "one billion, eight hundred sixty-four million, three hundred ninety-six thousand, eight hundred nine".