621808407 has 20 divisors (see below), whose sum is σ = 1013318856. Its totient is φ = 376853040.

The previous prime is 621808373. The next prime is 621808433. The reversal of 621808407 is 704808126.

It is not a de Polignac number, because 621808407 - 2¹⁰ = 621807383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621808207) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 348048 + ... + 349829.

Almost surely, 2^621808407 is an apocalyptic number.

621808407 is a deficient number, since it is larger than the sum of its proper divisors (391510449).

621808407 is a wasteful number, since it uses less digits than its factorization.

621808407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 697900 (or 697891 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 621808407 is about 24936.0864411399. The cubic root of 621808407 is about 853.5301430850.

The spelling of 621808407 in words is "six hundred twenty-one million, eight hundred eight thousand, four hundred seven".