621809473 has 4 divisors (see below), whose sum is σ = 621874260. Its totient is φ = 621744688.

The previous prime is 621809471. The next prime is 621809497. The reversal of 621809473 is 374908126.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 296115264 + 325694209 = 17208^2 + 18047^2 .

It is a cyclic number.

It is not a de Polignac number, because 621809473 - 2¹ = 621809471 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621809471) 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, 14818 + ... + 38251.

It is an arithmetic number, because the mean of its divisors is an integer number (155468565).

Almost surely, 2^621809473 is an apocalyptic number.

It is an amenable number.

621809473 is a deficient number, since it is larger than the sum of its proper divisors (64787).

621809473 is a wasteful number, since it uses less digits than its factorization.

621809473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64786.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 621809473 is about 24936.1078157759. The cubic root of 621809473 is about 853.5306308357.

The spelling of 621809473 in words is "six hundred twenty-one million, eight hundred nine thousand, four hundred seventy-three".