1621060081 has 2 divisors, whose sum is σ = 1621060082. Its totient is φ = 1621060080.

The previous prime is 1621060043. The next prime is 1621060097. The reversal of 1621060081 is 1800601261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1401753600 + 219306481 = 37440^2 + 14809^2 .

It is an emirp because it is prime and its reverse (1800601261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1621060081 - 2⁹ = 1621059569 is a prime.

It is a super-2 number, since 2×1621060081² = 5255671572423453122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1621060781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810530040 + 810530041.

It is an arithmetic number, because the mean of its divisors is an integer number (810530041).

Almost surely, 2^1621060081 is an apocalyptic number.

It is an amenable number.

1621060081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621060081 is an equidigital number, since it uses as much as digits as its factorization.

1621060081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 1621060081 is about 40262.3904034522. The cubic root of 1621060081 is about 1174.7164140731.

The spelling of 1621060081 in words is "one billion, six hundred twenty-one million, sixty thousand, eighty-one".