621605091 has 16 divisors (see below), whose sum is σ = 839083520. Its totient is φ = 409289760.

The previous prime is 621605077. The next prime is 621605093. The reversal of 621605091 is 190506126.

It is not a de Polignac number, because 621605091 - 2²⁶ = 554496227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621605093) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105366 + ... + 111108.

It is an arithmetic number, because the mean of its divisors is an integer number (52442720).

Almost surely, 2^621605091 is an apocalyptic number.

621605091 is a deficient number, since it is larger than the sum of its proper divisors (217478429).

621605091 is a wasteful number, since it uses less digits than its factorization.

621605091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6186.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 621605091 is about 24932.0093654723. The cubic root of 621605091 is about 853.4371051813.

The spelling of 621605091 in words is "six hundred twenty-one million, six hundred five thousand, ninety-one".