43442551021 has 2 divisors, whose sum is σ = 43442551022. Its totient is φ = 43442551020.

The previous prime is 43442550997. The next prime is 43442551049. The reversal of 43442551021 is 12015524434.

43442551021 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., 24300444996 + 19142106025 = 155886^2 + 138355^2 .

It is a cyclic number.

It is not a de Polignac number, because 43442551021 - 2³³ = 34852616429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43442551051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21721275510 + 21721275511.

It is an arithmetic number, because the mean of its divisors is an integer number (21721275511).

Almost surely, 2^43442551021 is an apocalyptic number.

It is an amenable number.

43442551021 is a deficient number, since it is larger than the sum of its proper divisors (1).

43442551021 is an equidigital number, since it uses as much as digits as its factorization.

43442551021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19200, while the sum is 31.

The spelling of 43442551021 in words is "forty-three billion, four hundred forty-two million, five hundred fifty-one thousand, twenty-one".