1233640891 has 8 divisors (see below), whose sum is σ = 1410295040. Its totient is φ = 1057091688.

The previous prime is 1233640843. The next prime is 1233640897. The reversal of 1233640891 is 1980463321.

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

It is a cyclic number.

It is not a de Polignac number, because 1233640891 - 2¹¹ = 1233638843 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1233640891.

It is not an unprimeable number, because it can be changed into a prime (1233640897) 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 7 ways as a sum of consecutive naturals, for example, 820 + ... + 49678.

It is an arithmetic number, because the mean of its divisors is an integer number (176286880).

Almost surely, 2^1233640891 is an apocalyptic number.

1233640891 is a deficient number, since it is larger than the sum of its proper divisors (176654149).

1233640891 is an equidigital number, since it uses as much as digits as its factorization.

1233640891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52473.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 1233640891 is about 35123.2243821663. The cubic root of 1233640891 is about 1072.4974100998.

The spelling of 1233640891 in words is "one billion, two hundred thirty-three million, six hundred forty thousand, eight hundred ninety-one".