1864320891 has 8 divisors (see below), whose sum is σ = 2511387984. Its totient is φ = 1230067200.

The previous prime is 1864320889. The next prime is 1864320949. The reversal of 1864320891 is 1980234681.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1864320891 - 2¹ = 1864320889 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1864320791) 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, 3203010 + ... + 3203591.

It is an arithmetic number, because the mean of its divisors is an integer number (313923498).

Almost surely, 2^1864320891 is an apocalyptic number.

1864320891 is a deficient number, since it is larger than the sum of its proper divisors (647067093).

1864320891 is an equidigital number, since it uses as much as digits as its factorization.

1864320891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6406701.

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 1864320891 is about 43177.7823770513. The cubic root of 1864320891 is about 1230.7605165175.

The spelling of 1864320891 in words is "one billion, eight hundred sixty-four million, three hundred twenty thousand, eight hundred ninety-one".