421815197 has 8 divisors (see below), whose sum is σ = 425604600. Its totient is φ = 418040064.

The previous prime is 421815187. The next prime is 421815211. The reversal of 421815197 is 791518124.

It can be written as a sum of positive squares in 4 ways, for example, as 200817241 + 220997956 = 14171^2 + 14866^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 421815197 - 2⁸ = 421814941 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 421815197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421815127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60929 + ... + 67497.

It is an arithmetic number, because the mean of its divisors is an integer number (53200575).

Almost surely, 2^421815197 is an apocalyptic number.

It is an amenable number.

421815197 is a deficient number, since it is larger than the sum of its proper divisors (3789403).

421815197 is a wasteful number, since it uses less digits than its factorization.

421815197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7135.

The product of its digits is 20160, while the sum is 38.

The square root of 421815197 is about 20538.1400569769. The cubic root of 421815197 is about 749.9645595105.

The spelling of 421815197 in words is "four hundred twenty-one million, eight hundred fifteen thousand, one hundred ninety-seven".