1821258349 has 4 divisors (see below), whose sum is σ = 1826064160. Its totient is φ = 1816452540.

The previous prime is 1821258347. The next prime is 1821258367. The reversal of 1821258349 is 9438521281.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1821258349 - 2¹ = 1821258347 is a prime.

It is a super-3 number, since 3×1821258349³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821258347) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2402337 + ... + 2403094.

It is an arithmetic number, because the mean of its divisors is an integer number (456516040).

Almost surely, 2^1821258349 is an apocalyptic number.

It is an amenable number.

1821258349 is a deficient number, since it is larger than the sum of its proper divisors (4805811).

1821258349 is an equidigital number, since it uses as much as digits as its factorization.

1821258349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4805810.

The product of its digits is 138240, while the sum is 43.

The square root of 1821258349 is about 42676.2035448328. The cubic root of 1821258349 is about 1221.2104686171.

The spelling of 1821258349 in words is "one billion, eight hundred twenty-one million, two hundred fifty-eight thousand, three hundred forty-nine".