218626649 has 2 divisors, whose sum is σ = 218626650. Its totient is φ = 218626648.

The previous prime is 218626627. The next prime is 218626669. The reversal of 218626649 is 946626812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 159567424 + 59059225 = 12632^2 + 7685^2 .

It is a cyclic number.

It is not a de Polignac number, because 218626649 - 2⁸ = 218626393 is a prime.

It is a super-2 number, since 2×218626649² = 95595223305938402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (218626619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109313324 + 109313325.

It is an arithmetic number, because the mean of its divisors is an integer number (109313325).

Almost surely, 2^218626649 is an apocalyptic number.

It is an amenable number.

218626649 is a deficient number, since it is larger than the sum of its proper divisors (1).

218626649 is an equidigital number, since it uses as much as digits as its factorization.

218626649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 44.

The square root of 218626649 is about 14786.0288448251. The cubic root of 218626649 is about 602.4222900986.

The spelling of 218626649 in words is "two hundred eighteen million, six hundred twenty-six thousand, six hundred forty-nine".