399262421 has 2 divisors, whose sum is σ = 399262422. Its totient is φ = 399262420.

The previous prime is 399262417. The next prime is 399262427. The reversal of 399262421 is 124262993.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 378886225 + 20376196 = 19465^2 + 4514^2 .

It is a cyclic number.

It is not a de Polignac number, because 399262421 - 2² = 399262417 is a prime.

It is a super-3 number, since 3×399262421³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399262427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199631210 + 199631211.

It is an arithmetic number, because the mean of its divisors is an integer number (199631211).

Almost surely, 2^399262421 is an apocalyptic number.

It is an amenable number.

399262421 is a deficient number, since it is larger than the sum of its proper divisors (1).

399262421 is an equidigital number, since it uses as much as digits as its factorization.

399262421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46656, while the sum is 38.

The square root of 399262421 is about 19981.5520167979. The cubic root of 399262421 is about 736.3531437037.

The spelling of 399262421 in words is "three hundred ninety-nine million, two hundred sixty-two thousand, four hundred twenty-one".