420508691 has 4 divisors (see below), whose sum is σ = 422622000. Its totient is φ = 418395384.

The previous prime is 420508687. The next prime is 420508709. The reversal of 420508691 is 196805024.

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 420508691 - 2² = 420508687 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (420508631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1056356 + ... + 1056753.

It is an arithmetic number, because the mean of its divisors is an integer number (105655500).

Almost surely, 2^420508691 is an apocalyptic number.

420508691 is a deficient number, since it is larger than the sum of its proper divisors (2113309).

420508691 is a wasteful number, since it uses less digits than its factorization.

420508691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2113308.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 420508691 is about 20506.3085659023. The cubic root of 420508691 is about 749.1894597556.

The spelling of 420508691 in words is "four hundred twenty million, five hundred eight thousand, six hundred ninety-one".