1620660149 has 2 divisors, whose sum is σ = 1620660150. Its totient is φ = 1620660148.

The previous prime is 1620660143. The next prime is 1620660163. The reversal of 1620660149 is 9410660261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1209300625 + 411359524 = 34775^2 + 20282^2 .

It is an emirp because it is prime and its reverse (9410660261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1620660149 - 2²⁴ = 1603882933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1620660143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810330074 + 810330075.

It is an arithmetic number, because the mean of its divisors is an integer number (810330075).

Almost surely, 2^1620660149 is an apocalyptic number.

It is an amenable number.

1620660149 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620660149 is an equidigital number, since it uses as much as digits as its factorization.

1620660149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 1620660149 is about 40257.4235265994. The cubic root of 1620660149 is about 1174.6198013007.

The spelling of 1620660149 in words is "one billion, six hundred twenty million, six hundred sixty thousand, one hundred forty-nine".