218057431 has 2 divisors, whose sum is σ = 218057432. Its totient is φ = 218057430.

The previous prime is 218057407. The next prime is 218057449. The reversal of 218057431 is 134750812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 218057431 - 2¹³ = 218049239 is a prime.

It is a super-2 number, since 2×218057431² = 95098086428639522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 218057393 and 218057402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218057461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109028715 + 109028716.

It is an arithmetic number, because the mean of its divisors is an integer number (109028716).

Almost surely, 2^218057431 is an apocalyptic number.

218057431 is a deficient number, since it is larger than the sum of its proper divisors (1).

218057431 is an equidigital number, since it uses as much as digits as its factorization.

218057431 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 218057431 is about 14766.7677912264. The cubic root of 218057431 is about 601.8990119520.

The spelling of 218057431 in words is "two hundred eighteen million, fifty-seven thousand, four hundred thirty-one".