642911 has 4 divisors (see below), whose sum is σ = 651792. Its totient is φ = 634032.

The previous prime is 642907. The next prime is 642931. The reversal of 642911 is 119246.

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 642911 - 2² = 642907 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 (642931) 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, 4331 + ... + 4476.

It is an arithmetic number, because the mean of its divisors is an integer number (162948).

2⁶⁴²⁹¹¹ is an apocalyptic number.

642911 is a deficient number, since it is larger than the sum of its proper divisors (8881).

642911 is an equidigital number, since it uses as much as digits as its factorization.

642911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8880.

The product of its digits is 432, while the sum is 23.

The square root of 642911 is about 801.8173108633. The cubic root of 642911 is about 86.3078474917.

The spelling of 642911 in words is "six hundred forty-two thousand, nine hundred eleven".