80821185421 has 2 divisors, whose sum is σ = 80821185422. Its totient is φ = 80821185420.

The previous prime is 80821185391. The next prime is 80821185461. The reversal of 80821185421 is 12458112808.

It is an a-pointer prime, because the next prime (80821185461) can be obtained adding 80821185421 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80775892521 + 45292900 = 284211^2 + 6730^2 .

It is a cyclic number.

It is not a de Polignac number, because 80821185421 - 2¹⁵ = 80821152653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80821185461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40410592710 + 40410592711.

It is an arithmetic number, because the mean of its divisors is an integer number (40410592711).

Almost surely, 2^80821185421 is an apocalyptic number.

It is an amenable number.

80821185421 is a deficient number, since it is larger than the sum of its proper divisors (1).

80821185421 is an equidigital number, since it uses as much as digits as its factorization.

80821185421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40960, while the sum is 40.

The spelling of 80821185421 in words is "eighty billion, eight hundred twenty-one million, one hundred eighty-five thousand, four hundred twenty-one".