42261391 has 2 divisors, whose sum is σ = 42261392. Its totient is φ = 42261390.

The previous prime is 42261361. The next prime is 42261397. The reversal of 42261391 is 19316224.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42261391 - 2⁹ = 42260879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42261397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21130695 + 21130696.

It is an arithmetic number, because the mean of its divisors is an integer number (21130696).

Almost surely, 2^42261391 is an apocalyptic number.

42261391 is a deficient number, since it is larger than the sum of its proper divisors (1).

42261391 is an equidigital number, since it uses as much as digits as its factorization.

42261391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 28.

The square root of 42261391 is about 6500.8761717172. The cubic root of 42261391 is about 348.3222864309.

The spelling of 42261391 in words is "forty-two million, two hundred sixty-one thousand, three hundred ninety-one".