1171725491 has 4 divisors (see below), whose sum is σ = 1172635800. Its totient is φ = 1170815184.

The previous prime is 1171725487. The next prime is 1171725521. The reversal of 1171725491 is 1945271711.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1945271711 = 43 ⋅45238877.

It is a cyclic number.

It is not a de Polignac number, because 1171725491 - 2² = 1171725487 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1171725091) 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, 453221 + ... + 455798.

It is an arithmetic number, because the mean of its divisors is an integer number (293158950).

Almost surely, 2^1171725491 is an apocalyptic number.

1171725491 is a deficient number, since it is larger than the sum of its proper divisors (910309).

1171725491 is an equidigital number, since it uses as much as digits as its factorization.

1171725491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910308.

The product of its digits is 17640, while the sum is 38.

The square root of 1171725491 is about 34230.4760557022. The cubic root of 1171725491 is about 1054.2459938894.

The spelling of 1171725491 in words is "one billion, one hundred seventy-one million, seven hundred twenty-five thousand, four hundred ninety-one".