218661628 has 6 divisors (see below), whose sum is σ = 382657856. Its totient is φ = 109330812.

The previous prime is 218661613. The next prime is 218661629. The reversal of 218661628 is 826166812.

It is a super-2 number, since 2×218661628² = 95625815119220768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218661629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27332700 + ... + 27332707.

Almost surely, 2^218661628 is an apocalyptic number.

It is an amenable number.

218661628 is a deficient number, since it is larger than the sum of its proper divisors (163996228).

218661628 is a wasteful number, since it uses less digits than its factorization.

218661628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54665411 (or 54665409 counting only the distinct ones).

The product of its digits is 55296, while the sum is 40.

The square root of 218661628 is about 14787.2116370870. The cubic root of 218661628 is about 602.4544164133.

The spelling of 218661628 in words is "two hundred eighteen million, six hundred sixty-one thousand, six hundred twenty-eight".