1566881 has 2 divisors, whose sum is σ = 1566882. Its totient is φ = 1566880.

The previous prime is 1566857. The next prime is 1566883. The reversal of 1566881 is 1886651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1254400 + 312481 = 1120^2 + 559^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1566881 is a prime.

It is a super-2 number, since 2×1566881² = 4910232136322, which contains 22 as substring.

Together with 1566883, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1566883) 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, 783440 + 783441.

It is an arithmetic number, because the mean of its divisors is an integer number (783441).

2^1566881 is an apocalyptic number.

It is an amenable number.

1566881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1566881 is an equidigital number, since it uses as much as digits as its factorization.

1566881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 35.

The square root of 1566881 is about 1251.7511733567. The cubic root of 1566881 is about 116.1480719073.

The spelling of 1566881 in words is "one million, five hundred sixty-six thousand, eight hundred eighty-one".