1821493641 has 16 divisors (see below), whose sum is σ = 2652592320. Its totient is φ = 1102624320.

The previous prime is 1821493637. The next prime is 1821493673. The reversal of 1821493641 is 1463941281.

It is not a de Polignac number, because 1821493641 - 2² = 1821493637 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1821493641.

It is not an unprimeable number, because it can be changed into a prime (1821491641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4206 + ... + 60503.

It is an arithmetic number, because the mean of its divisors is an integer number (165787020).

Almost surely, 2^1821493641 is an apocalyptic number.

1821493641 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1821493641 is a deficient number, since it is larger than the sum of its proper divisors (831098679).

1821493641 is a wasteful number, since it uses less digits than its factorization.

1821493641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65576.

The product of its digits is 41472, while the sum is 39.

The square root of 1821493641 is about 42678.9601677454. The cubic root of 1821493641 is about 1221.2630565582.

The spelling of 1821493641 in words is "one billion, eight hundred twenty-one million, four hundred ninety-three thousand, six hundred forty-one".