1565720064 has 160 divisors (see below), whose sum is σ = 4724295840. Its totient is φ = 511819776.

The previous prime is 1565720059. The next prime is 1565720087. The reversal of 1565720064 is 4600275651.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 731604 + ... + 733740.

It is an arithmetic number, because the mean of its divisors is an integer number (29526849).

Almost surely, 2^1565720064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1565720064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2362147920).

1565720064 is an abundant number, since it is smaller than the sum of its proper divisors (3158575776).

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

1565720064 is an equidigital number, since it uses as much as digits as its factorization.

1565720064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2217 (or 2195 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 1565720064 is about 39569.1807345060. The cubic root of 1565720064 is about 1161.1937928079.

It can be divided in two parts, 15657 and 20064, that added together give a square (35721 = 189²).

The spelling of 1565720064 in words is "one billion, five hundred sixty-five million, seven hundred twenty thousand, sixty-four".