1947984080521 has 2 divisors, whose sum is σ = 1947984080522. Its totient is φ = 1947984080520.

The previous prime is 1947984080477. The next prime is 1947984080561. The reversal of 1947984080521 is 1250804897491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1191075380496 + 756908700025 = 1091364^2 + 870005^2 .

It is a cyclic number.

It is not a de Polignac number, because 1947984080521 - 2²¹ = 1947981983369 is a prime.

It is not a weakly prime, because it can be changed into another prime (1947984080561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 973992040260 + 973992040261.

It is an arithmetic number, because the mean of its divisors is an integer number (973992040261).

Almost surely, 2^{1947984080521} is an apocalyptic number.

It is an amenable number.

1947984080521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1947984080521 is an equidigital number, since it uses as much as digits as its factorization.

1947984080521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5806080, while the sum is 58.

The spelling of 1947984080521 in words is "one trillion, nine hundred forty-seven billion, nine hundred eighty-four million, eighty thousand, five hundred twenty-one".