1564993601 has 4 divisors (see below), whose sum is σ = 1565088900. Its totient is φ = 1564898304.

The previous prime is 1564993597. The next prime is 1564993603. The reversal of 1564993601 is 1063994651.

It is a Cunningham number, because it is equal to 39560²+1.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1063994651 = 23 ⋅46260637.

It can be written as a sum of positive squares in 2 ways, for example, as 1546062400 + 18931201 = 39320^2 + 4351^2 .

It is a cyclic number.

It is not a de Polignac number, because 1564993601 - 2² = 1564993597 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1564993603) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16016 + ... + 58193.

It is an arithmetic number, because the mean of its divisors is an integer number (391272225).

Almost surely, 2^1564993601 is an apocalyptic number.

It is an amenable number.

1564993601 is a deficient number, since it is larger than the sum of its proper divisors (95299).

1564993601 is an equidigital number, since it uses as much as digits as its factorization.

1564993601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95298.

The product of its (nonzero) digits is 174960, while the sum is 44.

The square root of 1564993601 is about 39560.0000126390. Note that the first 4 decimals coincide. The cubic root of 1564993601 is about 1161.0141747427.

The spelling of 1564993601 in words is "one billion, five hundred sixty-four million, nine hundred ninety-three thousand, six hundred one".