1564991 has 2 divisors, whose sum is σ = 1564992. Its totient is φ = 1564990.

The previous prime is 1564949. The next prime is 1564993. The reversal of 1564991 is 1994651.

It is a strong prime.

It is an emirp because it is prime and its reverse (1994651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1564991 - 2¹⁰ = 1563967 is a prime.

Together with 1564993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1564993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 782495 + 782496.

It is an arithmetic number, because the mean of its divisors is an integer number (782496).

2^1564991 is an apocalyptic number.

1564991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1564991 is an equidigital number, since it uses as much as digits as its factorization.

1564991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9720, while the sum is 35.

The square root of 1564991 is about 1250.9960031911. The cubic root of 1564991 is about 116.1013531545.

The spelling of 1564991 in words is "one million, five hundred sixty-four thousand, nine hundred ninety-one".