1920391644 has 48 divisors (see below), whose sum is σ = 4534580736. Its totient is φ = 632486400.

The previous prime is 1920391643. The next prime is 1920391663. The reversal of 1920391644 is 4461930291.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1920391643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1059499 + ... + 1061309.

It is an arithmetic number, because the mean of its divisors is an integer number (94470432).

Almost surely, 2^1920391644 is an apocalyptic number.

It is an amenable number.

1920391644 is an abundant number, since it is smaller than the sum of its proper divisors (2614189092).

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

1920391644 is a wasteful number, since it uses less digits than its factorization.

1920391644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2826 (or 2824 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 1920391644 is about 43822.2733778155. The cubic root of 1920391644 is about 1242.9775055922.

The spelling of 1920391644 in words is "one billion, nine hundred twenty million, three hundred ninety-one thousand, six hundred forty-four".