396708421 has 2 divisors, whose sum is σ = 396708422. Its totient is φ = 396708420.

The previous prime is 396708419. The next prime is 396708449. The reversal of 396708421 is 124807693.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 364275396 + 32433025 = 19086^2 + 5695^2 .

It is a cyclic number.

It is not a de Polignac number, because 396708421 - 2¹ = 396708419 is a prime.

Together with 396708419, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_21169948 and since 396708421 and 21169948 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (396708401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198354210 + 198354211.

It is an arithmetic number, because the mean of its divisors is an integer number (198354211).

Almost surely, 2^396708421 is an apocalyptic number.

It is an amenable number.

396708421 is a deficient number, since it is larger than the sum of its proper divisors (1).

396708421 is an equidigital number, since it uses as much as digits as its factorization.

396708421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 396708421 is about 19917.5405359196. The cubic root of 396708421 is about 734.7796837624.

The spelling of 396708421 in words is "three hundred ninety-six million, seven hundred eight thousand, four hundred twenty-one".