1218922871 has 2 divisors, whose sum is σ = 1218922872. Its totient is φ = 1218922870.

The previous prime is 1218922853. The next prime is 1218922877. The reversal of 1218922871 is 1782298121.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1218922871 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1218922877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609461435 + 609461436.

It is an arithmetic number, because the mean of its divisors is an integer number (609461436).

Almost surely, 2^1218922871 is an apocalyptic number.

1218922871 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218922871 is an equidigital number, since it uses as much as digits as its factorization.

1218922871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 41.

The square root of 1218922871 is about 34913.0759315188. The cubic root of 1218922871 is about 1068.2151718849.

The spelling of 1218922871 in words is "one billion, two hundred eighteen million, nine hundred twenty-two thousand, eight hundred seventy-one".