1920821904 has 40 divisors (see below), whose sum is σ = 5513471520. Its totient is φ = 640273824.

The previous prime is 1920821893. The next prime is 1920821933. The reversal of 1920821904 is 4091280291.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2222742 + ... + 2223605.

It is an arithmetic number, because the mean of its divisors is an integer number (137836788).

Almost surely, 2^1920821904 is an apocalyptic number.

It is an amenable number.

1920821904 is an abundant number, since it is smaller than the sum of its proper divisors (3592649616).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1920821904 is a wasteful number, since it uses less digits than its factorization.

1920821904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4446364 (or 4446352 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 1920821904 is about 43827.1822502885. The cubic root of 1920821904 is about 1243.0703275551.

The spelling of 1920821904 in words is "one billion, nine hundred twenty million, eight hundred twenty-one thousand, nine hundred four".