42251639 has 2 divisors, whose sum is σ = 42251640. Its totient is φ = 42251638.

The previous prime is 42251623. The next prime is 42251701. The reversal of 42251639 is 93615224.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42251639 - 2⁴ = 42251623 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42151639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21125819 + 21125820.

It is an arithmetic number, because the mean of its divisors is an integer number (21125820).

Almost surely, 2^42251639 is an apocalyptic number.

42251639 is a deficient number, since it is larger than the sum of its proper divisors (1).

42251639 is an equidigital number, since it uses as much as digits as its factorization.

42251639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 32.

The square root of 42251639 is about 6500.1260757004. The cubic root of 42251639 is about 348.2954920750.

The spelling of 42251639 in words is "forty-two million, two hundred fifty-one thousand, six hundred thirty-nine".