218661451 has 2 divisors, whose sum is σ = 218661452. Its totient is φ = 218661450.

The previous prime is 218661433. The next prime is 218661467. The reversal of 218661451 is 154166812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 218661451 - 2⁵ = 218661419 is a prime.

It is not a weakly prime, because it can be changed into another prime (218661551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109330725 + 109330726.

It is an arithmetic number, because the mean of its divisors is an integer number (109330726).

Almost surely, 2^218661451 is an apocalyptic number.

218661451 is a deficient number, since it is larger than the sum of its proper divisors (1).

218661451 is an equidigital number, since it uses as much as digits as its factorization.

218661451 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 34.

The square root of 218661451 is about 14787.2056521846. The cubic root of 218661451 is about 602.4542538570.

The spelling of 218661451 in words is "two hundred eighteen million, six hundred sixty-one thousand, four hundred fifty-one".