1561615016 has 32 divisors (see below), whose sum is σ = 3319226400. Its totient is φ = 682810560.

The previous prime is 1561615001. The next prime is 1561615021. The reversal of 1561615016 is 6105161651.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 393170 + ... + 397121.

It is an arithmetic number, because the mean of its divisors is an integer number (103725825).

Almost surely, 2^1561615016 is an apocalyptic number.

It is an amenable number.

1561615016 is an abundant number, since it is smaller than the sum of its proper divisors (1757611384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1561615016 is a wasteful number, since it uses less digits than its factorization.

1561615016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790329 (or 790325 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 1561615016 is about 39517.2749060458. The cubic root of 1561615016 is about 1160.1780879967.

Adding to 1561615016 its reverse (6105161651), we get a palindrome (7666776667).

The spelling of 1561615016 in words is "one billion, five hundred sixty-one million, six hundred fifteen thousand, sixteen".