1891225728 has 96 divisors (see below), whose sum is σ = 6219682560. Its totient is φ = 540347904.

The previous prime is 1891225709. The next prime is 1891225729. The reversal of 1891225728 is 8275221981.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (1891225729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 109200 + ... + 125327.

It is an arithmetic number, because the mean of its divisors is an integer number (64788360).

Almost surely, 2^1891225728 is an apocalyptic number.

1891225728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1891225728 is an abundant number, since it is smaller than the sum of its proper divisors (4328456832).

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

1891225728 is a wasteful number, since it uses less digits than its factorization.

1891225728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234554 (or 234539 counting only the distinct ones).

The product of its digits is 161280, while the sum is 45.

The square root of 1891225728 is about 43488.2251649800. The cubic root of 1891225728 is about 1236.6528112729.

The spelling of 1891225728 in words is "one billion, eight hundred ninety-one million, two hundred twenty-five thousand, seven hundred twenty-eight".