1891133890 has 32 divisors (see below), whose sum is σ = 3610863360. Its totient is φ = 710655744.

The previous prime is 1891133833. The next prime is 1891133891. The reversal of 1891133890 is 983311981.

It is not an unprimeable number, because it can be changed into a prime (1891133891) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85831 + ... + 105589.

It is an arithmetic number, because the mean of its divisors is an integer number (112839480).

Almost surely, 2^1891133890 is an apocalyptic number.

1891133890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1891133890 is a deficient number, since it is larger than the sum of its proper divisors (1719729470).

1891133890 is a wasteful number, since it uses less digits than its factorization.

1891133890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20346.

The product of its (nonzero) digits is 46656, while the sum is 43.

The square root of 1891133890 is about 43487.1692571499. The cubic root of 1891133890 is about 1236.6327936449.

The spelling of 1891133890 in words is "one billion, eight hundred ninety-one million, one hundred thirty-three thousand, eight hundred ninety".