421242620165 has 4 divisors (see below), whose sum is σ = 505491144204. Its totient is φ = 336994096128.

The previous prime is 421242620131. The next prime is 421242620173. The reversal of 421242620165 is 561026242124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 58749518689 + 362493101476 = 242383^2 + 602074^2 .

It is a cyclic number.

It is not a de Polignac number, because 421242620165 - 2¹⁸ = 421242358021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 42124262012 + ... + 42124262021.

It is an arithmetic number, because the mean of its divisors is an integer number (126372786051).

Almost surely, 2^421242620165 is an apocalyptic number.

It is an amenable number.

421242620165 is a deficient number, since it is larger than the sum of its proper divisors (84248524039).

421242620165 is an equidigital number, since it uses as much as digits as its factorization.

421242620165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84248524038.

The product of its (nonzero) digits is 46080, while the sum is 35.

Adding to 421242620165 its reverse (561026242124), we get a palindrome (982268862289).

The spelling of 421242620165 in words is "four hundred twenty-one billion, two hundred forty-two million, six hundred twenty thousand, one hundred sixty-five".