1921843636 has 24 divisors (see below), whose sum is σ = 3477277440. Its totient is φ = 928435200.

The previous prime is 1921843633. The next prime is 1921843657. The reversal of 1921843636 is 6363481291.

It is a super-2 number, since 2×1921843636² = 7386965922467400992, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1921843592 and 1921843601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1921843631) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 67395 + ... + 91573.

It is an arithmetic number, because the mean of its divisors is an integer number (144886560).

Almost surely, 2^1921843636 is an apocalyptic number.

It is an amenable number.

1921843636 is a deficient number, since it is larger than the sum of its proper divisors (1555433804).

1921843636 is a wasteful number, since it uses less digits than its factorization.

1921843636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24855 (or 24853 counting only the distinct ones).

The product of its digits is 186624, while the sum is 43.

The square root of 1921843636 is about 43838.8370739918. The cubic root of 1921843636 is about 1243.2906949578.

The spelling of 1921843636 in words is "one billion, nine hundred twenty-one million, eight hundred forty-three thousand, six hundred thirty-six".