621656093 has 4 divisors (see below), whose sum is σ = 643092540. Its totient is φ = 600219648.

The previous prime is 621656023. The next prime is 621656099. The reversal of 621656093 is 390656126.

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

It can be written as a sum of positive squares in 2 ways, for example, as 227315929 + 394340164 = 15077^2 + 19858^2 .

It is a cyclic number.

It is not a de Polignac number, because 621656093 - 2¹⁴ = 621639709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621656099) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10718180 + ... + 10718237.

It is an arithmetic number, because the mean of its divisors is an integer number (160773135).

Almost surely, 2^621656093 is an apocalyptic number.

It is an amenable number.

621656093 is a deficient number, since it is larger than the sum of its proper divisors (21436447).

621656093 is a wasteful number, since it uses less digits than its factorization.

621656093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21436446.

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 621656093 is about 24933.0321661847. The cubic root of 621656093 is about 853.4604457285.

The spelling of 621656093 in words is "six hundred twenty-one million, six hundred fifty-six thousand, ninety-three".