1608697994 has 4 divisors (see below), whose sum is σ = 2413046994. Its totient is φ = 804348996.

The previous prime is 1608697967. The next prime is 1608697997. The reversal of 1608697994 is 4997968061.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4997968061 = 38047 ⋅131363.

It can be written as a sum of positive squares in only one way, i.e., 1417899025 + 190798969 = 37655^2 + 13813^2 .

It is not an unprimeable number, because it can be changed into a prime (1608697997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402174497 + ... + 402174500.

Almost surely, 2^1608697994 is an apocalyptic number.

1608697994 is a deficient number, since it is larger than the sum of its proper divisors (804349000).

1608697994 is an equidigital number, since it uses as much as digits as its factorization.

1608697994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804348999.

The product of its (nonzero) digits is 5878656, while the sum is 59.

The square root of 1608697994 is about 40108.5775614145. The cubic root of 1608697994 is about 1171.7226903339.

The spelling of 1608697994 in words is "one billion, six hundred eight million, six hundred ninety-seven thousand, nine hundred ninety-four".