1564870721 has 2 divisors, whose sum is σ = 1564870722. Its totient is φ = 1564870720.

The previous prime is 1564870709. The next prime is 1564870733. The reversal of 1564870721 is 1270784651.

It is a balanced prime because it is at equal distance from previous prime (1564870709) and next prime (1564870733).

It can be written as a sum of positive squares in only one way, i.e., 1373740096 + 191130625 = 37064^2 + 13825^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1564870721 is a prime.

It is not a weakly prime, because it can be changed into another prime (1564876721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 782435360 + 782435361.

It is an arithmetic number, because the mean of its divisors is an integer number (782435361).

Almost surely, 2^1564870721 is an apocalyptic number.

It is an amenable number.

1564870721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1564870721 is an equidigital number, since it uses as much as digits as its factorization.

1564870721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 94080, while the sum is 41.

The square root of 1564870721 is about 39558.4468982290. The cubic root of 1564870721 is about 1160.9837871518.

The spelling of 1564870721 in words is "one billion, five hundred sixty-four million, eight hundred seventy thousand, seven hundred twenty-one".