1661060081 has 2 divisors, whose sum is σ = 1661060082. Its totient is φ = 1661060080.

The previous prime is 1661060059. The next prime is 1661060117. The reversal of 1661060081 is 1800601661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1627315600 + 33744481 = 40340^2 + 5809^2 .

It is an emirp because it is prime and its reverse (1800601661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1661060081 - 2⁶ = 1661060017 is a prime.

It is a super-3 number, since 3×1661060081³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (1661060381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830530040 + 830530041.

It is an arithmetic number, because the mean of its divisors is an integer number (830530041).

Almost surely, 2^1661060081 is an apocalyptic number.

It is an amenable number.

1661060081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661060081 is an equidigital number, since it uses as much as digits as its factorization.

1661060081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 1661060081 is about 40756.1048310557. The cubic root of 1661060081 is about 1184.3001394807.

The spelling of 1661060081 in words is "one billion, six hundred sixty-one million, sixty thousand, eighty-one".