1565163640 has 64 divisors (see below), whose sum is σ = 3741616800. Its totient is φ = 588123648.

The previous prime is 1565163601. The next prime is 1565163641. The reversal of 1565163640 is 463615651.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a self number, because there is not a number n which added to its sum of digits gives 1565163640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1565163641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24687 + ... + 61153.

Almost surely, 2^1565163640 is an apocalyptic number.

1565163640 is a gapful number since it is divisible by the number (10) 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 1565163640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1870808400).

1565163640 is an abundant number, since it is smaller than the sum of its proper divisors (2176453160).

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

1565163640 is a wasteful number, since it uses less digits than its factorization.

1565163640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36544 (or 36540 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 1565163640 is about 39562.1490821720. The cubic root of 1565163640 is about 1161.0562218880.

The spelling of 1565163640 in words is "one billion, five hundred sixty-five million, one hundred sixty-three thousand, six hundred forty".