1561650066503 has 4 divisors (see below), whose sum is σ = 1561691862600. Its totient is φ = 1561608270408.

The previous prime is 1561650066463. The next prime is 1561650066511. The reversal of 1561650066503 is 3056600561651.

It is a happy number.

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 1561650066503 - 2¹² = 1561650062407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561650066553) 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, 20841953 + ... + 20916746.

It is an arithmetic number, because the mean of its divisors is an integer number (390422965650).

Almost surely, 2^{1561650066503} is an apocalyptic number.

1561650066503 is a deficient number, since it is larger than the sum of its proper divisors (41796097).

1561650066503 is an equidigital number, since it uses as much as digits as its factorization.

1561650066503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41796096.

The product of its (nonzero) digits is 486000, while the sum is 44.

The spelling of 1561650066503 in words is "one trillion, five hundred sixty-one billion, six hundred fifty million, sixty-six thousand, five hundred three".