1564405668 has 72 divisors (see below), whose sum is σ = 4553989440. Its totient is φ = 443551680.

The previous prime is 1564405657. The next prime is 1564405673. The reversal of 1564405668 is 8665044651.

1564405668 is a `hidden beast` number, since 156 + 440 + 56 + 6 + 8 = 666.

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, 9318 + ... + 56706.

Almost surely, 2^1564405668 is an apocalyptic number.

1564405668 is a gapful number since it is divisible by the number (18) 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 1564405668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2276994720).

1564405668 is an abundant number, since it is smaller than the sum of its proper divisors (2989583772).

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

1564405668 is a wasteful number, since it uses less digits than its factorization.

1564405668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47537 (or 47532 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The square root of 1564405668 is about 39552.5684121777. The cubic root of 1564405668 is about 1160.8687675361.

The spelling of 1564405668 in words is "one billion, five hundred sixty-four million, four hundred five thousand, six hundred sixty-eight".