242891391 has 16 divisors (see below), whose sum is σ = 334502784. Its totient is φ = 156674784.

The previous prime is 242891381. The next prime is 242891399. The reversal of 242891391 is 193198242.

It is not a de Polignac number, because 242891391 - 2⁷ = 242891263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (242891399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5005 + ... + 22601.

It is an arithmetic number, because the mean of its divisors is an integer number (20906424).

Almost surely, 2^242891391 is an apocalyptic number.

242891391 is a deficient number, since it is larger than the sum of its proper divisors (91611393).

242891391 is a wasteful number, since it uses less digits than its factorization.

242891391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17750.

The product of its digits is 31104, while the sum is 39.

The square root of 242891391 is about 15584.9732434804. The cubic root of 242891391 is about 623.9321635863.

The spelling of 242891391 in words is "two hundred forty-two million, eight hundred ninety-one thousand, three hundred ninety-one".