1620716161 has 2 divisors, whose sum is σ = 1620716162. Its totient is φ = 1620716160.

The previous prime is 1620716147. The next prime is 1620716179. The reversal of 1620716161 is 1616170261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1228081936 + 392634225 = 35044^2 + 19815^2 .

It is a cyclic number.

It is not a de Polignac number, because 1620716161 - 2²³ = 1612327553 is a prime.

It is not a weakly prime, because it can be changed into another prime (1620716261) 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, 810358080 + 810358081.

It is an arithmetic number, because the mean of its divisors is an integer number (810358081).

Almost surely, 2^1620716161 is an apocalyptic number.

It is an amenable number.

1620716161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620716161 is an equidigital number, since it uses as much as digits as its factorization.

1620716161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 1620716161 is about 40258.1191935242. The cubic root of 1620716161 is about 1174.6333332446.

The spelling of 1620716161 in words is "one billion, six hundred twenty million, seven hundred sixteen thousand, one hundred sixty-one".