1051208891 has 4 divisors (see below), whose sum is σ = 1051646232. Its totient is φ = 1050771552.

The previous prime is 1051208819. The next prime is 1051208903. The reversal of 1051208891 is 1988021501.

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 1051208891 - 2¹⁰ = 1051207867 is a prime.

It is a super-2 number, since 2×1051208891² = 2210080265034899762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1054208891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215045 + ... + 219878.

It is an arithmetic number, because the mean of its divisors is an integer number (262911558).

Almost surely, 2^1051208891 is an apocalyptic number.

1051208891 is a deficient number, since it is larger than the sum of its proper divisors (437341).

1051208891 is an equidigital number, since it uses as much as digits as its factorization.

1051208891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437340.

The product of its (nonzero) digits is 5760, while the sum is 35.

The square root of 1051208891 is about 32422.3517191459. The cubic root of 1051208891 is about 1016.7862746436.

The spelling of 1051208891 in words is "one billion, fifty-one million, two hundred eight thousand, eight hundred ninety-one".