1666061522 has 4 divisors (see below), whose sum is σ = 2499092286. Its totient is φ = 833030760.

The previous prime is 1666061497. The next prime is 1666061543. The reversal of 1666061522 is 2251606661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 2251606661 = 29 ⋅77641609.

It can be written as a sum of positive squares in only one way, i.e., 1499160961 + 166900561 = 38719^2 + 12919^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416515379 + ... + 416515382.

Almost surely, 2^1666061522 is an apocalyptic number.

1666061522 is a deficient number, since it is larger than the sum of its proper divisors (833030764).

1666061522 is an equidigital number, since it uses as much as digits as its factorization.

1666061522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 833030763.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 1666061522 is about 40817.4168952422. The cubic root of 1666061522 is about 1185.4875884585.

The spelling of 1666061522 in words is "one billion, six hundred sixty-six million, sixty-one thousand, five hundred twenty-two".