993965902421 has 2 divisors, whose sum is σ = 993965902422. Its totient is φ = 993965902420.

The previous prime is 993965902379. The next prime is 993965902529. The reversal of 993965902421 is 124209569399.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 834034695025 + 159931207396 = 913255^2 + 399914^2 .

It is an emirp because it is prime and its reverse (124209569399) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-993965902421 is a prime.

It is a super-2 number, since 2×993965902421² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (993965907421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 496982951210 + 496982951211.

It is an arithmetic number, because the mean of its divisors is an integer number (496982951211).

Almost surely, 2^993965902421 is an apocalyptic number.

It is an amenable number.

993965902421 is a deficient number, since it is larger than the sum of its proper divisors (1).

993965902421 is an equidigital number, since it uses as much as digits as its factorization.

993965902421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9447840, while the sum is 59.

The spelling of 993965902421 in words is "nine hundred ninety-three billion, nine hundred sixty-five million, nine hundred two thousand, four hundred twenty-one".