994648274457821 has 2 divisors, whose sum is σ = 994648274457822. Its totient is φ = 994648274457820.

The previous prime is 994648274457767. The next prime is 994648274457863. The reversal of 994648274457821 is 128754472846499.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 769796899905796 + 224851374552025 = 27745214^2 + 14995045^2 .

It is an emirp because it is prime and its reverse (128754472846499) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-994648274457821 is a prime.

It is a super-2 number, since 2×994648274457821² (a number of 31 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (994648574457821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 497324137228910 + 497324137228911.

It is an arithmetic number, because the mean of its divisors is an integer number (497324137228911).

Almost surely, 2^{994648274457821} is an apocalyptic number.

It is an amenable number.

994648274457821 is a deficient number, since it is larger than the sum of its proper divisors (1).

994648274457821 is an equidigital number, since it uses as much as digits as its factorization.

994648274457821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7803371520, while the sum is 80.

The spelling of 994648274457821 in words is "nine hundred ninety-four trillion, six hundred forty-eight billion, two hundred seventy-four million, four hundred fifty-seven thousand, eight hundred twenty-one".