1661605151 has 2 divisors, whose sum is σ = 1661605152. Its totient is φ = 1661605150.

The previous prime is 1661605133. The next prime is 1661605171. The reversal of 1661605151 is 1515061661.

It is a weak prime.

It is an emirp because it is prime and its reverse (1515061661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1661605151 - 2¹⁴ = 1661588767 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661605111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830802575 + 830802576.

It is an arithmetic number, because the mean of its divisors is an integer number (830802576).

Almost surely, 2^1661605151 is an apocalyptic number.

1661605151 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661605151 is an equidigital number, since it uses as much as digits as its factorization.

1661605151 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 1661605151 is about 40762.7912562425. The cubic root of 1661605151 is about 1184.4296663791.

The spelling of 1661605151 in words is "one billion, six hundred sixty-one million, six hundred five thousand, one hundred fifty-one".