1561164503 has 4 divisors (see below), whose sum is σ = 1599241728. Its totient is φ = 1523087280.

The previous prime is 1561164499. The next prime is 1561164533. The reversal of 1561164503 is 3054611651.

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

It is a cyclic number.

It is not a de Polignac number, because 1561164503 - 2² = 1561164499 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1561164503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561164533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19038551 + ... + 19038632.

It is an arithmetic number, because the mean of its divisors is an integer number (399810432).

Almost surely, 2^1561164503 is an apocalyptic number.

1561164503 is a deficient number, since it is larger than the sum of its proper divisors (38077225).

1561164503 is an equidigital number, since it uses as much as digits as its factorization.

1561164503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38077224.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 1561164503 is about 39511.5742915921. The cubic root of 1561164503 is about 1160.0665100093.

The spelling of 1561164503 in words is "one billion, five hundred sixty-one million, one hundred sixty-four thousand, five hundred three".