996817421 has 2 divisors, whose sum is σ = 996817422. Its totient is φ = 996817420.

The previous prime is 996817399. The next prime is 996817427. The reversal of 996817421 is 124718699.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 985332100 + 11485321 = 31390^2 + 3389^2 .

It is a cyclic number.

It is not a de Polignac number, because 996817421 - 2¹⁴ = 996801037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (996817427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498408710 + 498408711.

It is an arithmetic number, because the mean of its divisors is an integer number (498408711).

Almost surely, 2^996817421 is an apocalyptic number.

It is an amenable number.

996817421 is a deficient number, since it is larger than the sum of its proper divisors (1).

996817421 is an equidigital number, since it uses as much as digits as its factorization.

996817421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 47.

The square root of 996817421 is about 31572.4155078448. The cubic root of 996817421 is about 998.9380129160.

The spelling of 996817421 in words is "nine hundred ninety-six million, eight hundred seventeen thousand, four hundred twenty-one".