621155 has 4 divisors (see below), whose sum is σ = 745392. Its totient is φ = 496920.

The previous prime is 621143. The next prime is 621217. The reversal of 621155 is 551126.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 621155 - 2⁴ = 621139 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62111 + ... + 62120.

It is an arithmetic number, because the mean of its divisors is an integer number (186348).

2⁶²¹¹⁵⁵ is an apocalyptic number.

621155 is a deficient number, since it is larger than the sum of its proper divisors (124237).

621155 is a wasteful number, since it uses less digits than its factorization.

621155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124236.

The product of its digits is 300, while the sum is 20.

The square root of 621155 is about 788.1338718771. The cubic root of 621155 is about 85.3231070238.

The spelling of 621155 in words is "six hundred twenty-one thousand, one hundred fifty-five".