1980010178521 has 2 divisors, whose sum is σ = 1980010178522. Its totient is φ = 1980010178520.

The previous prime is 1980010178417. The next prime is 1980010178527. The reversal of 1980010178521 is 1258710100891.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1789805162896 + 190205015625 = 1337836^2 + 436125^2 .

It is a cyclic number.

It is not a de Polignac number, because 1980010178521 - 2⁹ = 1980010178009 is a prime.

It is not a weakly prime, because it can be changed into another prime (1980010178527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990005089260 + 990005089261.

It is an arithmetic number, because the mean of its divisors is an integer number (990005089261).

Almost surely, 2^{1980010178521} is an apocalyptic number.

It is an amenable number.

1980010178521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1980010178521 is an equidigital number, since it uses as much as digits as its factorization.

1980010178521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 43.

The spelling of 1980010178521 in words is "one trillion, nine hundred eighty billion, ten million, one hundred seventy-eight thousand, five hundred twenty-one".