1561626463 has 4 divisors (see below), whose sum is σ = 1566050688. Its totient is φ = 1557202240.

The previous prime is 1561626461. The next prime is 1561626499. The reversal of 1561626463 is 3646261651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3646261651 = 41 ⋅88933211.

It is a cyclic number.

It is not a de Polignac number, because 1561626463 - 2¹ = 1561626461 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561626461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2211583 + ... + 2212288.

It is an arithmetic number, because the mean of its divisors is an integer number (391512672).

Almost surely, 2^1561626463 is an apocalyptic number.

1561626463 is a deficient number, since it is larger than the sum of its proper divisors (4424225).

1561626463 is an equidigital number, since it uses as much as digits as its factorization.

1561626463 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4424224.

The product of its digits is 155520, while the sum is 40.

The square root of 1561626463 is about 39517.4197411724. The cubic root of 1561626463 is about 1160.1809227812.

The spelling of 1561626463 in words is "one billion, five hundred sixty-one million, six hundred twenty-six thousand, four hundred sixty-three".