621732401 has 4 divisors (see below), whose sum is σ = 622685172. Its totient is φ = 620779632.

The previous prime is 621732359. The next prime is 621732443. The reversal of 621732401 is 104237126.

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

It is an interprime number because it is at equal distance from previous prime (621732359) and next prime (621732443).

It can be written as a sum of positive squares in 2 ways, for example, as 212722225 + 409010176 = 14585^2 + 20224^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621732401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621732101) 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, 475406 + ... + 476711.

It is an arithmetic number, because the mean of its divisors is an integer number (155671293).

Almost surely, 2^621732401 is an apocalyptic number.

It is an amenable number.

621732401 is a deficient number, since it is larger than the sum of its proper divisors (952771).

621732401 is an equidigital number, since it uses as much as digits as its factorization.

621732401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 952770.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 621732401 is about 24934.5623783535. The cubic root of 621732401 is about 853.4953649257.

Adding to 621732401 its reverse (104237126), we get a palindrome (725969527).

The spelling of 621732401 in words is "six hundred twenty-one million, seven hundred thirty-two thousand, four hundred one".