1561563616 has 24 divisors (see below), whose sum is σ = 3075857064. Its totient is φ = 780393600.

The previous prime is 1561563613. The next prime is 1561563749. The reversal of 1561563616 is 6163651651.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561563613) 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, 59791 + ... + 81841.

It is an arithmetic number, because the mean of its divisors is an integer number (128160711).

Almost surely, 2^1561563616 is an apocalyptic number.

1561563616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1561563616 is a deficient number, since it is larger than the sum of its proper divisors (1514293448).

1561563616 is a wasteful number, since it uses less digits than its factorization.

1561563616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24274 (or 24266 counting only the distinct ones).

The product of its digits is 97200, while the sum is 40.

The square root of 1561563616 is about 39516.6245522059. The cubic root of 1561563616 is about 1160.1653589080.

The spelling of 1561563616 in words is "one billion, five hundred sixty-one million, five hundred sixty-three thousand, six hundred sixteen".