621728018 has 8 divisors (see below), whose sum is σ = 955338300. Its totient is φ = 303281920.

The previous prime is 621727991. The next prime is 621728087. The reversal of 621728018 is 810827126.

It can be written as a sum of positive squares in 2 ways, for example, as 393506569 + 228221449 = 19837^2 + 15107^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3790943 + ... + 3791106.

Almost surely, 2^621728018 is an apocalyptic number.

621728018 is a deficient number, since it is larger than the sum of its proper divisors (333610282).

621728018 is a wasteful number, since it uses less digits than its factorization.

621728018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7582092.

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 621728018 is about 24934.4744881459. The cubic root of 621728018 is about 853.4933593045.

The spelling of 621728018 in words is "six hundred twenty-one million, seven hundred twenty-eight thousand, eighteen".