1172943661 has 4 divisors (see below), whose sum is σ = 1173845152. Its totient is φ = 1172042172.

The previous prime is 1172943647. The next prime is 1172943677. The reversal of 1172943661 is 1663492711.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1172943661 - 2¹⁹ = 1172419373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1172943601) 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, 448791 + ... + 451396.

It is an arithmetic number, because the mean of its divisors is an integer number (293461288).

Almost surely, 2^1172943661 is an apocalyptic number.

It is an amenable number.

1172943661 is a deficient number, since it is larger than the sum of its proper divisors (901491).

1172943661 is an equidigital number, since it uses as much as digits as its factorization.

1172943661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 901490.

The product of its digits is 54432, while the sum is 40.

The square root of 1172943661 is about 34248.2650801468. The cubic root of 1172943661 is about 1054.6112119823.

The spelling of 1172943661 in words is "one billion, one hundred seventy-two million, nine hundred forty-three thousand, six hundred sixty-one".