239872421 has 2 divisors, whose sum is σ = 239872422. Its totient is φ = 239872420.

The previous prime is 239872357. The next prime is 239872433. The reversal of 239872421 is 124278932.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 227587396 + 12285025 = 15086^2 + 3505^2 .

It is a cyclic number.

It is not a de Polignac number, because 239872421 - 2⁶ = 239872357 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a plaindrome in base 11.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (239872441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 119936210 + 119936211.

It is an arithmetic number, because the mean of its divisors is an integer number (119936211).

Almost surely, 2^239872421 is an apocalyptic number.

It is an amenable number.

239872421 is a deficient number, since it is larger than the sum of its proper divisors (1).

239872421 is an equidigital number, since it uses as much as digits as its factorization.

239872421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 38.

The square root of 239872421 is about 15487.8152429579. The cubic root of 239872421 is about 621.3363656688.

The spelling of 239872421 in words is "two hundred thirty-nine million, eight hundred seventy-two thousand, four hundred twenty-one".