42402251 has 2 divisors, whose sum is σ = 42402252. Its totient is φ = 42402250.

The previous prime is 42402247. The next prime is 42402277. The reversal of 42402251 is 15220424.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42402251 - 2² = 42402247 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42402551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21201125 + 21201126.

It is an arithmetic number, because the mean of its divisors is an integer number (21201126).

Almost surely, 2^42402251 is an apocalyptic number.

42402251 is a deficient number, since it is larger than the sum of its proper divisors (1).

42402251 is an equidigital number, since it uses as much as digits as its factorization.

42402251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 42402251 is about 6511.7010834343. The cubic root of 42402251 is about 348.7088509751.

Adding to 42402251 its reverse (15220424), we get a palindrome (57622675).

The spelling of 42402251 in words is "forty-two million, four hundred two thousand, two hundred fifty-one".