1551917 has 2 divisors, whose sum is σ = 1551918. Its totient is φ = 1551916.

The previous prime is 1551911. The next prime is 1551919. The reversal of 1551917 is 7191551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1503076 + 48841 = 1226^2 + 221^2 .

It is an emirp because it is prime and its reverse (7191551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1551917 - 2⁶ = 1551853 is a prime.

Together with 1551919, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1551917.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1551911) 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 as a sum of consecutive naturals, namely, 775958 + 775959.

It is an arithmetic number, because the mean of its divisors is an integer number (775959).

2^1551917 is an apocalyptic number.

It is an amenable number.

1551917 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551917 is an equidigital number, since it uses as much as digits as its factorization.

1551917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1575, while the sum is 29.

The square root of 1551917 is about 1245.7596076290. The cubic root of 1551917 is about 115.7771434710. Note that the first 3 decimals are identical.

The spelling of 1551917 in words is "one million, five hundred fifty-one thousand, nine hundred seventeen".