1661157577 has 2 divisors, whose sum is σ = 1661157578. Its totient is φ = 1661157576.

The previous prime is 1661157539. The next prime is 1661157623. The reversal of 1661157577 is 7757511661.

It is an a-pointer prime, because the next prime (1661157623) can be obtained adding 1661157577 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 988222096 + 672935481 = 31436^2 + 25941^2 .

It is a cyclic number.

It is not a de Polignac number, because 1661157577 - 2¹⁵ = 1661124809 is a prime.

It is not a weakly prime, because it can be changed into another prime (1661157877) 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, 830578788 + 830578789.

It is an arithmetic number, because the mean of its divisors is an integer number (830578789).

Almost surely, 2^1661157577 is an apocalyptic number.

It is an amenable number.

1661157577 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661157577 is an equidigital number, since it uses as much as digits as its factorization.

1661157577 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 308700, while the sum is 46.

The square root of 1661157577 is about 40757.3009042552. The cubic root of 1661157577 is about 1184.3233098783.

The spelling of 1661157577 in words is "one billion, six hundred sixty-one million, one hundred fifty-seven thousand, five hundred seventy-seven".