421686515818 has 8 divisors (see below), whose sum is σ = 638792445060. Its totient is φ = 208755700800.

The previous prime is 421686515801. The next prime is 421686515821. The reversal of 421686515818 is 818515686124.

It can be written as a sum of positive squares in 2 ways, for example, as 408240489969 + 13446025849 = 638937^2 + 115957^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1043778303 + ... + 1043778706.

Almost surely, 2^421686515818 is an apocalyptic number.

421686515818 is a deficient number, since it is larger than the sum of its proper divisors (217105929242).

421686515818 is a wasteful number, since it uses less digits than its factorization.

421686515818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2087557112.

The product of its digits is 3686400, while the sum is 55.

The spelling of 421686515818 in words is "four hundred twenty-one billion, six hundred eighty-six million, five hundred fifteen thousand, eight hundred eighteen".