43631867621 has 2 divisors, whose sum is σ = 43631867622. Its totient is φ = 43631867620.

The previous prime is 43631867603. The next prime is 43631867681. The reversal of 43631867621 is 12676813634.

43631867621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35555250721 + 8076616900 = 188561^2 + 89870^2 .

It is a cyclic number.

It is not a de Polignac number, because 43631867621 - 2⁶ = 43631867557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43631867681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21815933810 + 21815933811.

It is an arithmetic number, because the mean of its divisors is an integer number (21815933811).

Almost surely, 2^43631867621 is an apocalyptic number.

It is an amenable number.

43631867621 is a deficient number, since it is larger than the sum of its proper divisors (1).

43631867621 is an equidigital number, since it uses as much as digits as its factorization.

43631867621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 47.

The spelling of 43631867621 in words is "forty-three billion, six hundred thirty-one million, eight hundred sixty-seven thousand, six hundred twenty-one".