421661807 has 18 divisors (see below), whose sum is σ = 495625032. Its totient is φ = 357677544.

The previous prime is 421661803. The next prime is 421661831. The reversal of 421661807 is 708166124.

It is not a de Polignac number, because 421661807 - 2² = 421661803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421661803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1857428 + ... + 1857654.

It is an arithmetic number, because the mean of its divisors is an integer number (27534724).

Almost surely, 2^421661807 is an apocalyptic number.

421661807 is a deficient number, since it is larger than the sum of its proper divisors (73963225).

421661807 is an equidigital number, since it uses as much as digits as its factorization.

421661807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 635 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 421661807 is about 20534.4054454956. The cubic root of 421661807 is about 749.8736421202.

The spelling of 421661807 in words is "four hundred twenty-one million, six hundred sixty-one thousand, eight hundred seven".