218400449 has 4 divisors (see below), whose sum is σ = 220067760. Its totient is φ = 216733140.

The previous prime is 218400443. The next prime is 218400499. The reversal of 218400449 is 944004812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 218400449 - 2¹⁶ = 218334913 is a prime.

It is a super-2 number, since 2×218400449² = 95397512246803202, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218400443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 833459 + ... + 833720.

It is an arithmetic number, because the mean of its divisors is an integer number (55016940).

Almost surely, 2^218400449 is an apocalyptic number.

It is an amenable number.

218400449 is a deficient number, since it is larger than the sum of its proper divisors (1667311).

218400449 is a wasteful number, since it uses less digits than its factorization.

218400449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1667310.

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 218400449 is about 14778.3777526493. The cubic root of 218400449 is about 602.2144548906.

The spelling of 218400449 in words is "two hundred eighteen million, four hundred thousand, four hundred forty-nine".