621945 has 32 divisors (see below), whose sum is σ = 1175040. Its totient is φ = 311040.

The previous prime is 621941. The next prime is 621983. The reversal of 621945 is 549126.

621945 is nontrivially palindromic in base 16.

It is not a de Polignac number, because 621945 - 2² = 621941 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (621941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2160 + ... + 2430.

It is an arithmetic number, because the mean of its divisors is an integer number (36720).

2⁶²¹⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

621945 is a deficient number, since it is larger than the sum of its proper divisors (553095).

621945 is a wasteful number, since it uses less digits than its factorization.

621945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302 (or 296 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 621945 is about 788.6348965142. The cubic root of 621945 is about 85.3592636990.

The spelling of 621945 in words is "six hundred twenty-one thousand, nine hundred forty-five".