621671985 has 144 divisors (see below), whose sum is σ = 1274757120. Its totient is φ = 279417600.

The previous prime is 621671959. The next prime is 621671987. The reversal of 621671985 is 589176126.

621671985 is a `hidden beast` number, since 621 + 6 + 7 + 19 + 8 + 5 = 666.

621671985 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 621671985 - 2⁷ = 621671857 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 621671985.

It is not an unprimeable number, because it can be changed into a prime (621671987) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 4894992 + ... + 4895118.

It is an arithmetic number, because the mean of its divisors is an integer number (8852480).

Almost surely, 2^621671985 is an apocalyptic number.

It is an amenable number.

621671985 is an abundant number, since it is smaller than the sum of its proper divisors (653085135).

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

621671985 is a wasteful number, since it uses less digits than its factorization.

621671985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220 (or 206 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 621671985 is about 24933.3508578370. The cubic root of 621671985 is about 853.4677182799.

The spelling of 621671985 in words is "six hundred twenty-one million, six hundred seventy-one thousand, nine hundred eighty-five".