1665616474 has 4 divisors (see below), whose sum is σ = 2498424714. Its totient is φ = 832808236.

The previous prime is 1665616471. The next prime is 1665616489. The reversal of 1665616474 is 4746165661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4746165661 = 307 ⋅15459823.

It can be written as a sum of positive squares in only one way, i.e., 1420913025 + 244703449 = 37695^2 + 15643^2 .

It is not an unprimeable number, because it can be changed into a prime (1665616471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416404117 + ... + 416404120.

Almost surely, 2^1665616474 is an apocalyptic number.

1665616474 is a deficient number, since it is larger than the sum of its proper divisors (832808240).

1665616474 is an equidigital number, since it uses as much as digits as its factorization.

1665616474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832808239.

The product of its digits is 725760, while the sum is 46.

The square root of 1665616474 is about 40811.9648387578. The cubic root of 1665616474 is about 1185.3820209552.

The spelling of 1665616474 in words is "one billion, six hundred sixty-five million, six hundred sixteen thousand, four hundred seventy-four".