1551647 has 2 divisors, whose sum is σ = 1551648. Its totient is φ = 1551646.

The previous prime is 1551623. The next prime is 1551659. The reversal of 1551647 is 7461551.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1551647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1551617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775823 + 775824.

It is an arithmetic number, because the mean of its divisors is an integer number (775824).

2^1551647 is an apocalyptic number.

1551647 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551647 is an equidigital number, since it uses as much as digits as its factorization.

1551647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4200, while the sum is 29.

The square root of 1551647 is about 1245.6512352982. The cubic root of 1551647 is about 115.7704288418.

The spelling of 1551647 in words is "one million, five hundred fifty-one thousand, six hundred forty-seven".