1215647 has 2 divisors, whose sum is σ = 1215648. Its totient is φ = 1215646.

The previous prime is 1215637. The next prime is 1215649. The reversal of 1215647 is 7465121.

It is a strong prime.

It is an emirp because it is prime and its reverse (7465121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1215647 - 2⁴ = 1215631 is a prime.

Together with 1215649, 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 (1215649) 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, 607823 + 607824.

It is an arithmetic number, because the mean of its divisors is an integer number (607824).

2^1215647 is an apocalyptic number.

1215647 is a deficient number, since it is larger than the sum of its proper divisors (1).

1215647 is an equidigital number, since it uses as much as digits as its factorization.

1215647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1680, while the sum is 26.

The square root of 1215647 is about 1102.5638303518. The cubic root of 1215647 is about 106.7257365964.

The spelling of 1215647 in words is "one million, two hundred fifteen thousand, six hundred forty-seven".