1001272891 has 4 divisors (see below), whose sum is σ = 1014989032. Its totient is φ = 987556752.

The previous prime is 1001272889. The next prime is 1001272901. The reversal of 1001272891 is 1982721001.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1001272891 - 2¹ = 1001272889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1001272861) 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 3 ways as a sum of consecutive naturals, for example, 6857961 + ... + 6858106.

It is an arithmetic number, because the mean of its divisors is an integer number (253747258).

Almost surely, 2^1001272891 is an apocalyptic number.

1001272891 is a deficient number, since it is larger than the sum of its proper divisors (13716141).

1001272891 is an equidigital number, since it uses as much as digits as its factorization.

1001272891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13716140.

The product of its (nonzero) digits is 2016, while the sum is 31.

The square root of 1001272891 is about 31642.8963750160. The cubic root of 1001272891 is about 1000.4241170993.

Adding to 1001272891 its reverse (1982721001), we get a palindrome (2983993892).

The spelling of 1001272891 in words is "one billion, one million, two hundred seventy-two thousand, eight hundred ninety-one".