621541421 has 4 divisors (see below), whose sum is σ = 626286144. Its totient is φ = 616796700.

The previous prime is 621541411. The next prime is 621541439. The reversal of 621541421 is 124145126.

621541421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621541421 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621541411) 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, 2372165 + ... + 2372426.

It is an arithmetic number, because the mean of its divisors is an integer number (156571536).

Almost surely, 2^621541421 is an apocalyptic number.

It is an amenable number.

621541421 is a deficient number, since it is larger than the sum of its proper divisors (4744723).

621541421 is a wasteful number, since it uses less digits than its factorization.

621541421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4744722.

The product of its digits is 1920, while the sum is 26.

The square root of 621541421 is about 24930.7324601585. The cubic root of 621541421 is about 853.4079654608.

Adding to 621541421 its reverse (124145126), we get a palindrome (745686547).

The spelling of 621541421 in words is "six hundred twenty-one million, five hundred forty-one thousand, four hundred twenty-one".