1566161720 has 32 divisors (see below), whose sum is σ = 3731151600. Its totient is φ = 589613568.

The previous prime is 1566161719. The next prime is 1566161731. The reversal of 1566161720 is 271616651.

It is a congruent number.

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, 1150910 + ... + 1152269.

Almost surely, 2^1566161720 is an apocalyptic number.

1566161720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1566161720 is an abundant number, since it is smaller than the sum of its proper divisors (2164989880).

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

1566161720 is a wasteful number, since it uses less digits than its factorization.

1566161720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2303207 (or 2303203 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 1566161720 is about 39574.7611489949. The cubic root of 1566161720 is about 1161.3029651528.

The spelling of 1566161720 in words is "one billion, five hundred sixty-six million, one hundred sixty-one thousand, seven hundred twenty".