1661516041 has 2 divisors, whose sum is σ = 1661516042. Its totient is φ = 1661516040.

The previous prime is 1661516039. The next prime is 1661516069. The reversal of 1661516041 is 1406151661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1073938441 + 587577600 = 32771^2 + 24240^2 .

It is a cyclic number.

It is not a de Polignac number, because 1661516041 - 2¹ = 1661516039 is a prime.

Together with 1661516039, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1661515994 and 1661516012.

It is not a weakly prime, because it can be changed into another prime (1661516741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830758020 + 830758021.

It is an arithmetic number, because the mean of its divisors is an integer number (830758021).

Almost surely, 2^1661516041 is an apocalyptic number.

It is an amenable number.

1661516041 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661516041 is an equidigital number, since it uses as much as digits as its factorization.

1661516041 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 1661516041 is about 40761.6982104524. The cubic root of 1661516041 is about 1184.4084927940.

The spelling of 1661516041 in words is "one billion, six hundred sixty-one million, five hundred sixteen thousand, forty-one".