1611994157 has 2 divisors, whose sum is σ = 1611994158. Its totient is φ = 1611994156.

The previous prime is 1611994129. The next prime is 1611994193. The reversal of 1611994157 is 7514991161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1521858121 + 90136036 = 39011^2 + 9494^2 .

It is an emirp because it is prime and its reverse (7514991161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1611994157 - 2³⁰ = 538252333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1611994117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 805997078 + 805997079.

It is an arithmetic number, because the mean of its divisors is an integer number (805997079).

Almost surely, 2^1611994157 is an apocalyptic number.

It is an amenable number.

1611994157 is a deficient number, since it is larger than the sum of its proper divisors (1).

1611994157 is an equidigital number, since it uses as much as digits as its factorization.

1611994157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68040, while the sum is 44.

The square root of 1611994157 is about 40149.6470345631. The cubic root of 1611994157 is about 1172.5224166060.

The spelling of 1611994157 in words is "one billion, six hundred eleven million, nine hundred ninety-four thousand, one hundred fifty-seven".