621661543 has 2 divisors, whose sum is σ = 621661544. Its totient is φ = 621661542.

The previous prime is 621661517. The next prime is 621661561. The reversal of 621661543 is 345166126.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 621661543 - 2⁹ = 621661031 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 621661499 and 621661508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621061543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310830771 + 310830772.

It is an arithmetic number, because the mean of its divisors is an integer number (310830772).

Almost surely, 2^621661543 is an apocalyptic number.

621661543 is a deficient number, since it is larger than the sum of its proper divisors (1).

621661543 is an equidigital number, since it uses as much as digits as its factorization.

621661543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 34.

The square root of 621661543 is about 24933.1414587091. The cubic root of 621661543 is about 853.4629397901.

The spelling of 621661543 in words is "six hundred twenty-one million, six hundred sixty-one thousand, five hundred forty-three".