621504601 has 4 divisors (see below), whose sum is σ = 621609892. Its totient is φ = 621399312.

The previous prime is 621504571. The next prime is 621504607. The reversal of 621504601 is 106405126.

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 265201225 + 356303376 = 16285^2 + 18876^2 .

It is a cyclic number.

It is not a de Polignac number, because 621504601 - 2²⁵ = 587950169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621504607) 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 3 ways as a sum of consecutive naturals, for example, 43230 + ... + 55783.

It is an arithmetic number, because the mean of its divisors is an integer number (155402473).

Almost surely, 2^621504601 is an apocalyptic number.

It is an amenable number.

621504601 is a deficient number, since it is larger than the sum of its proper divisors (105291).

621504601 is an equidigital number, since it uses as much as digits as its factorization.

621504601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105290.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 621504601 is about 24929.9940032083. The cubic root of 621504601 is about 853.3911132174.

Adding to 621504601 its reverse (106405126), we get a palindrome (727909727).

The spelling of 621504601 in words is "six hundred twenty-one million, five hundred four thousand, six hundred one".