1171553947 has 4 divisors (see below), whose sum is σ = 1172190096. Its totient is φ = 1170917800.

The previous prime is 1171553917. The next prime is 1171553989. The reversal of 1171553947 is 7493551711.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7493551711 = 15647 ⋅478913.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1171553947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1171553917) 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, 315304 + ... + 318997.

It is an arithmetic number, because the mean of its divisors is an integer number (293047524).

Almost surely, 2^1171553947 is an apocalyptic number.

1171553947 is a deficient number, since it is larger than the sum of its proper divisors (636149).

1171553947 is an equidigital number, since it uses as much as digits as its factorization.

1171553947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636148.

The product of its digits is 132300, while the sum is 43.

The square root of 1171553947 is about 34227.9702436472. The cubic root of 1171553947 is about 1054.1945431579.

The spelling of 1171553947 in words is "one billion, one hundred seventy-one million, five hundred fifty-three thousand, nine hundred forty-seven".