1821434685 has 32 divisors (see below), whose sum is σ = 3385235712. Its totient is φ = 819002880.

The previous prime is 1821434647. The next prime is 1821434687. The reversal of 1821434685 is 5864341281.

It is a happy number.

It is not a de Polignac number, because 1821434685 - 2¹⁰ = 1821433661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821434687) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 135784 + ... + 148593.

It is an arithmetic number, because the mean of its divisors is an integer number (105788616).

Almost surely, 2^1821434685 is an apocalyptic number.

1821434685 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1821434685 is a deficient number, since it is larger than the sum of its proper divisors (1563801027).

1821434685 is a wasteful number, since it uses less digits than its factorization.

1821434685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284453.

The product of its digits is 184320, while the sum is 42.

The square root of 1821434685 is about 42678.2694705397. The cubic root of 1821434685 is about 1221.2498802725.

The spelling of 1821434685 in words is "one billion, eight hundred twenty-one million, four hundred thirty-four thousand, six hundred eighty-five".