1661605522 has 4 divisors (see below), whose sum is σ = 2492408286. Its totient is φ = 830802760.

The previous prime is 1661605507. The next prime is 1661605531. The reversal of 1661605522 is 2255061661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1645032481 + 16573041 = 40559^2 + 4071^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415401379 + ... + 415401382.

Almost surely, 2^1661605522 is an apocalyptic number.

1661605522 is a deficient number, since it is larger than the sum of its proper divisors (830802764).

1661605522 is an equidigital number, since it uses as much as digits as its factorization.

1661605522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830802763.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 1661605522 is about 40762.7958069610. The cubic root of 1661605522 is about 1184.4297545315.

The spelling of 1661605522 in words is "one billion, six hundred sixty-one million, six hundred five thousand, five hundred twenty-two".