1821127645 has 8 divisors (see below), whose sum is σ = 2260710360. Its totient is φ = 1406664000.

The previous prime is 1821127639. The next prime is 1821127657. The reversal of 1821127645 is 5467211281.

It can be written as a sum of positive squares in 4 ways, for example, as 531671364 + 1289456281 = 23058^2 + 35909^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1821127645 - 2¹³ = 1821119453 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6279606 + ... + 6279895.

It is an arithmetic number, because the mean of its divisors is an integer number (282588795).

Almost surely, 2^1821127645 is an apocalyptic number.

It is an amenable number.

1821127645 is a deficient number, since it is larger than the sum of its proper divisors (439582715).

1821127645 is a wasteful number, since it uses less digits than its factorization.

1821127645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12559535.

The product of its digits is 26880, while the sum is 37.

The square root of 1821127645 is about 42674.6721721445. The cubic root of 1821127645 is about 1221.1812542167.

The spelling of 1821127645 in words is "one billion, eight hundred twenty-one million, one hundred twenty-seven thousand, six hundred forty-five".