421667567 has 4 divisors (see below), whose sum is σ = 422313960. Its totient is φ = 421021176.

The previous prime is 421667539. The next prime is 421667573. The reversal of 421667567 is 765766124.

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 421667567 - 2¹² = 421663471 is a prime.

It is a super-4 number, since 4×421667567⁴ (a number of 36 digits) contains 4444 as substring. Note that it is a super-d number also for d = 3.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421667537) 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, 322217 + ... + 323522.

It is an arithmetic number, because the mean of its divisors is an integer number (105578490).

Almost surely, 2^421667567 is an apocalyptic number.

421667567 is a deficient number, since it is larger than the sum of its proper divisors (646393).

421667567 is an equidigital number, since it uses as much as digits as its factorization.

421667567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646392.

The product of its digits is 423360, while the sum is 44.

The square root of 421667567 is about 20534.5456974339. The cubic root of 421667567 is about 749.8770565884.

The spelling of 421667567 in words is "four hundred twenty-one million, six hundred sixty-seven thousand, five hundred sixty-seven".