218661354 has 12 divisors (see below), whose sum is σ = 473766306. Its totient is φ = 72887112.

The previous prime is 218661349. The next prime is 218661371. The reversal of 218661354 is 453166812.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 134444025 + 84217329 = 11595^2 + 9177^2 .

It is a super-2 number, since 2×218661354² = 95625575466226632, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6073909 + ... + 6073944.

Almost surely, 2^218661354 is an apocalyptic number.

218661354 is an abundant number, since it is smaller than the sum of its proper divisors (255104952).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218661354 is a wasteful number, since it uses less digits than its factorization.

218661354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12147861 (or 12147858 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 218661354 is about 14787.2023723218. The cubic root of 218661354 is about 602.4541647724.

It can be divided in two parts, 21866 and 1354, that added together give a triangular number (23220 = T₂₁₅).

The spelling of 218661354 in words is "two hundred eighteen million, six hundred sixty-one thousand, three hundred fifty-four".