1242215647 has 4 divisors (see below), whose sum is σ = 1242395080. Its totient is φ = 1242036216.

The previous prime is 1242215633. The next prime is 1242215683. The reversal of 1242215647 is 7465122421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7465122421 = 1151 ⋅6485771.

It is a cyclic number.

It is not a de Polignac number, because 1242215647 - 2¹⁹ = 1241691359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1242215627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78897 + ... + 93322.

It is an arithmetic number, because the mean of its divisors is an integer number (310598770).

Almost surely, 2^1242215647 is an apocalyptic number.

1242215647 is a deficient number, since it is larger than the sum of its proper divisors (179433).

1242215647 is an equidigital number, since it uses as much as digits as its factorization.

1242215647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179432.

The product of its digits is 26880, while the sum is 34.

The square root of 1242215647 is about 35245.0797559035. The cubic root of 1242215647 is about 1074.9765697435.

The spelling of 1242215647 in words is "one billion, two hundred forty-two million, two hundred fifteen thousand, six hundred forty-seven".