1218739 has 2 divisors, whose sum is σ = 1218740. Its totient is φ = 1218738.

The previous prime is 1218731. The next prime is 1218761. The reversal of 1218739 is 9378121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1218739 - 2³ = 1218731 is a prime.

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 1218739.

It is not a weakly prime, because it can be changed into another prime (1218731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609369 + 609370.

It is an arithmetic number, because the mean of its divisors is an integer number (609370).

2^1218739 is an apocalyptic number.

1218739 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218739 is an equidigital number, since it uses as much as digits as its factorization.

1218739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 31.

The square root of 1218739 is about 1103.9651262608. The cubic root of 1218739 is about 106.8161456791.

The spelling of 1218739 in words is "one million, two hundred eighteen thousand, seven hundred thirty-nine".