1991624804 has 24 divisors (see below), whose sum is σ = 3780463680. Its totient is φ = 912595104.

The previous prime is 1991624801. The next prime is 1991624857. The reversal of 1991624804 is 4084261991.

It is not an unprimeable number, because it can be changed into a prime (1991624801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130544 + ... + 144999.

It is an arithmetic number, because the mean of its divisors is an integer number (157519320).

Almost surely, 2^1991624804 is an apocalyptic number.

It is an amenable number.

1991624804 is a deficient number, since it is larger than the sum of its proper divisors (1788838876).

1991624804 is a wasteful number, since it uses less digits than its factorization.

1991624804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275699 (or 275697 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 1991624804 is about 44627.6237772078. The cubic root of 1991624804 is about 1258.1599083285.

The spelling of 1991624804 in words is "one billion, nine hundred ninety-one million, six hundred twenty-four thousand, eight hundred four".