238878721 has 2 divisors, whose sum is σ = 238878722. Its totient is φ = 238878720.

The previous prime is 238878709. The next prime is 238878727. The reversal of 238878721 is 127878832.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 237160000 + 1718721 = 15400^2 + 1311^2 .

It is a cyclic number.

It is not a de Polignac number, because 238878721 - 2¹³ = 238870529 is a prime.

It is not a weakly prime, because it can be changed into another prime (238878727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 119439360 + 119439361.

It is an arithmetic number, because the mean of its divisors is an integer number (119439361).

It is a Proth number, since it is equal to 3645 ⋅ 2¹⁶ + 1 and 3645 < 2¹⁶.

Almost surely, 2^238878721 is an apocalyptic number.

It is an amenable number.

238878721 is a deficient number, since it is larger than the sum of its proper divisors (1).

238878721 is an equidigital number, since it uses as much as digits as its factorization.

238878721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 301056, while the sum is 46.

The square root of 238878721 is about 15455.7018928291. The cubic root of 238878721 is about 620.4771915950.

The spelling of 238878721 in words is "two hundred thirty-eight million, eight hundred seventy-eight thousand, seven hundred twenty-one".