218121000 has 64 divisors (see below), whose sum is σ = 680546880. Its totient is φ = 58164800.

The previous prime is 218120993. The next prime is 218121011. The reversal of 218121000 is 121812.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33354 + ... + 39353.

It is an arithmetic number, because the mean of its divisors is an integer number (10633545).

Almost surely, 2^218121000 is an apocalyptic number.

218121000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218121000 is an abundant number, since it is smaller than the sum of its proper divisors (462425880).

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

218121000 is a wasteful number, since it uses less digits than its factorization.

218121000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72731 (or 72717 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 218121000 is about 14768.9200688473. The cubic root of 218121000 is about 601.9574956286.

Adding to 218121000 its reverse (121812), we get a palindrome (218242812).

The spelling of 218121000 in words is "two hundred eighteen million, one hundred twenty-one thousand".