621928018 has 4 divisors (see below), whose sum is σ = 932892030. Its totient is φ = 310964008.

The previous prime is 621927989. The next prime is 621928019. The reversal of 621928018 is 810829126.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 810829126 = 2 ⋅405414563.

It can be written as a sum of positive squares in only one way, i.e., 621654489 + 273529 = 24933^2 + 523^2 .

It is not an unprimeable number, because it can be changed into a prime (621928019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155482003 + ... + 155482006.

Almost surely, 2^621928018 is an apocalyptic number.

621928018 is a deficient number, since it is larger than the sum of its proper divisors (310964012).

621928018 is a wasteful number, since it uses less digits than its factorization.

621928018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310964011.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 621928018 is about 24938.4846773015. The cubic root of 621928018 is about 853.5848678991.

The spelling of 621928018 in words is "six hundred twenty-one million, nine hundred twenty-eight thousand, eighteen".