426991 has 4 divisors (see below), whose sum is σ = 433432. Its totient is φ = 420552.

The previous prime is 426973. The next prime is 426997. The reversal of 426991 is 199624.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 426991 - 2⁷ = 426863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (426997) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3120 + ... + 3253.

It is an arithmetic number, because the mean of its divisors is an integer number (108358).

2⁴²⁶⁹⁹¹ is an apocalyptic number.

426991 is a deficient number, since it is larger than the sum of its proper divisors (6441).

426991 is an equidigital number, since it uses as much as digits as its factorization.

426991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6440.

The product of its digits is 3888, while the sum is 31.

The square root of 426991 is about 653.4454835715. The cubic root of 426991 is about 75.3019530635.

The spelling of 426991 in words is "four hundred twenty-six thousand, nine hundred ninety-one".