1551791 has 2 divisors, whose sum is σ = 1551792. Its totient is φ = 1551790.

The previous prime is 1551773. The next prime is 1551793. The reversal of 1551791 is 1971551.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1551791 is a prime.

Together with 1551793, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₁₁₇₇₈₅ and since 1551791 and 117785 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1551793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775895 + 775896.

It is an arithmetic number, because the mean of its divisors is an integer number (775896).

2^1551791 is an apocalyptic number.

1551791 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551791 is an equidigital number, since it uses as much as digits as its factorization.

1551791 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 1551791 is about 1245.7090350479. The cubic root of 1551791 is about 115.7740100743.

The spelling of 1551791 in words is "one million, five hundred fifty-one thousand, seven hundred ninety-one".