1821261944 has 16 divisors (see below), whose sum is σ = 3532620600. Its totient is φ = 879229792.

The previous prime is 1821261931. The next prime is 1821261983. The reversal of 1821261944 is 4491621281.

It is a junction number, because it is equal to n+sod(n) for n = 1821261898 and 1821261907.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 3924902 + ... + 3925365.

Almost surely, 2^1821261944 is an apocalyptic number.

It is an amenable number.

1821261944 is a deficient number, since it is larger than the sum of its proper divisors (1711358656).

1821261944 is a wasteful number, since it uses less digits than its factorization.

1821261944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7850302 (or 7850298 counting only the distinct ones).

The product of its digits is 27648, while the sum is 38.

The square root of 1821261944 is about 42676.2456643037. The cubic root of 1821261944 is about 1221.2112721364.

The spelling of 1821261944 in words is "one billion, eight hundred twenty-one million, two hundred sixty-one thousand, nine hundred forty-four".