1820672865 has 48 divisors (see below), whose sum is σ = 3447924480. Its totient is φ = 881418240.

The previous prime is 1820672863. The next prime is 1820672923. The reversal of 1820672865 is 5682760281.

It is not a de Polignac number, because 1820672865 - 2¹ = 1820672863 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 1820672865.

It is not an unprimeable number, because it can be changed into a prime (1820672863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 378264 + ... + 383046.

It is an arithmetic number, because the mean of its divisors is an integer number (71831760).

Almost surely, 2^1820672865 is an apocalyptic number.

1820672865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1820672865 is a deficient number, since it is larger than the sum of its proper divisors (1627251615).

1820672865 is a wasteful number, since it uses less digits than its factorization.

1820672865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5574 (or 5571 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The square root of 1820672865 is about 42669.3433860893. The cubic root of 1820672865 is about 1221.0795928370.

The spelling of 1820672865 in words is "one billion, eight hundred twenty million, six hundred seventy-two thousand, eight hundred sixty-five".