999993874626521 has 2 divisors, whose sum is σ = 999993874626522. Its totient is φ = 999993874626520.

The previous prime is 999993874626443. The next prime is 999993874626613. The reversal of 999993874626521 is 125626478399999.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 737555008625296 + 262438866001225 = 27157964^2 + 16199965^2 .

It is a cyclic number.

It is not a de Polignac number, because 999993874626521 - 2⁴² = 995595828115417 is a prime.

It is not a weakly prime, because it can be changed into another prime (999993874626221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499996937313260 + 499996937313261.

It is an arithmetic number, because the mean of its divisors is an integer number (499996937313261).

Almost surely, 2^{999993874626521} is an apocalyptic number.

It is an amenable number.

999993874626521 is a deficient number, since it is larger than the sum of its proper divisors (1).

999993874626521 is an equidigital number, since it uses as much as digits as its factorization.

999993874626521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28570268160, while the sum is 89.

The spelling of 999993874626521 in words is "nine hundred ninety-nine trillion, nine hundred ninety-three billion, eight hundred seventy-four million, six hundred twenty-six thousand, five hundred twenty-one".