80440000021 has 2 divisors, whose sum is σ = 80440000022. Its totient is φ = 80440000020.

The previous prime is 80439999977. The next prime is 80440000027. The reversal of 80440000021 is 12000004408.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62807878225 + 17632121796 = 250615^2 + 132786^2 .

It is a cyclic number.

It is not a de Polignac number, because 80440000021 - 2¹¹ = 80439997973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80440000027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40220000010 + 40220000011.

It is an arithmetic number, because the mean of its divisors is an integer number (40220000011).

Almost surely, 2^80440000021 is an apocalyptic number.

It is an amenable number.

80440000021 is a deficient number, since it is larger than the sum of its proper divisors (1).

80440000021 is an equidigital number, since it uses as much as digits as its factorization.

80440000021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 80440000021 its reverse (12000004408), we get a palindrome (92440004429).

The spelling of 80440000021 in words is "eighty billion, four hundred forty million, twenty-one", and thus it is an aban number.