1565166816 has 144 divisors (see below), whose sum is σ = 4537587600. Its totient is φ = 511678464.

The previous prime is 1565166791. The next prime is 1565166851. The reversal of 1565166816 is 6186615651.

1565166816 is a `hidden beast` number, since 1 + 56 + 516 + 6 + 81 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5818330 + ... + 5818598.

It is an arithmetic number, because the mean of its divisors is an integer number (31511025).

Almost surely, 2^1565166816 is an apocalyptic number.

1565166816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1565166816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2268793800).

1565166816 is an abundant number, since it is smaller than the sum of its proper divisors (2972420784).

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

1565166816 is a wasteful number, since it uses less digits than its factorization.

1565166816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 601 (or 590 counting only the distinct ones).

The product of its digits is 259200, while the sum is 45.

The square root of 1565166816 is about 39562.1892215282. The cubic root of 1565166816 is about 1161.0570072184.

The spelling of 1565166816 in words is "one billion, five hundred sixty-five million, one hundred sixty-six thousand, eight hundred sixteen".