996996421 has 2 divisors, whose sum is σ = 996996422. Its totient is φ = 996996420.

The previous prime is 996996397. The next prime is 996996437. The reversal of 996996421 is 124699699.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 643180321 + 353816100 = 25361^2 + 18810^2 .

It is a cyclic number.

It is not a de Polignac number, because 996996421 - 2⁵ = 996996389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (996996461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498498210 + 498498211.

It is an arithmetic number, because the mean of its divisors is an integer number (498498211).

Almost surely, 2^996996421 is an apocalyptic number.

It is an amenable number.

996996421 is a deficient number, since it is larger than the sum of its proper divisors (1).

996996421 is an equidigital number, since it uses as much as digits as its factorization.

996996421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1889568, while the sum is 55.

The square root of 996996421 is about 31575.2501336094. The cubic root of 996996421 is about 998.9978029366.

The spelling of 996996421 in words is "nine hundred ninety-six million, nine hundred ninety-six thousand, four hundred twenty-one".