1561242623 has 4 divisors (see below), whose sum is σ = 1573536000. Its totient is φ = 1548949248.

The previous prime is 1561242587. The next prime is 1561242629. The reversal of 1561242623 is 3262421651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3262421651 = 3767 ⋅866053.

It is a cyclic number.

It is not a de Polignac number, because 1561242623 - 2¹⁰ = 1561241599 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 1561242623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561242629) 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, 6146498 + ... + 6146751.

It is an arithmetic number, because the mean of its divisors is an integer number (393384000).

Almost surely, 2^1561242623 is an apocalyptic number.

1561242623 is a deficient number, since it is larger than the sum of its proper divisors (12293377).

1561242623 is a wasteful number, since it uses less digits than its factorization.

1561242623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12293376.

The product of its digits is 17280, while the sum is 32.

The square root of 1561242623 is about 39512.5628503138. The cubic root of 1561242623 is about 1160.0858594296.

The spelling of 1561242623 in words is "one billion, five hundred sixty-one million, two hundred forty-two thousand, six hundred twenty-three".