1091976491 has 4 divisors (see below), whose sum is σ = 1092384672. Its totient is φ = 1091568312.

The previous prime is 1091976383. The next prime is 1091976503. The reversal of 1091976491 is 1946791901.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1091976491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1091976091) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200051 + ... + 205436.

It is an arithmetic number, because the mean of its divisors is an integer number (273096168).

Almost surely, 2^1091976491 is an apocalyptic number.

1091976491 is a deficient number, since it is larger than the sum of its proper divisors (408181).

1091976491 is an equidigital number, since it uses as much as digits as its factorization.

1091976491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408180.

The product of its (nonzero) digits is 122472, while the sum is 47.

The square root of 1091976491 is about 33045.0675744505. The cubic root of 1091976491 is about 1029.7641370887.

The spelling of 1091976491 in words is "one billion, ninety-one million, nine hundred seventy-six thousand, four hundred ninety-one".