1561011516 has 18 divisors (see below), whose sum is σ = 3945890312. Its totient is φ = 520337160.

The previous prime is 1561011511. The next prime is 1561011523. The reversal of 1561011516 is 6151101651.

It is a tau number, because it is divible by the number of its divisors (18).

It is a self number, because there is not a number n which added to its sum of digits gives 1561011516.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561011511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21680680 + ... + 21680751.

Almost surely, 2^1561011516 is an apocalyptic number.

It is an amenable number.

1561011516 is an abundant number, since it is smaller than the sum of its proper divisors (2384878796).

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

1561011516 is a wasteful number, since it uses less digits than its factorization.

1561011516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43361441 (or 43361436 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 27.

The square root of 1561011516 is about 39509.6382671368. The cubic root of 1561011516 is about 1160.0286150294.

The spelling of 1561011516 in words is "one billion, five hundred sixty-one million, eleven thousand, five hundred sixteen".