421402404324521 has 16 divisors (see below), whose sum is σ = 442558752242880. Its totient is φ = 400836902667840.

The previous prime is 421402404324511. The next prime is 421402404324527. The reversal of 421402404324521 is 125423404204124.

It is a cyclic number.

It is not a de Polignac number, because 421402404324521 - 2⁶ = 421402404324457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (421402404324527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 532859591 + ... + 533649836.

It is an arithmetic number, because the mean of its divisors is an integer number (27659922015180).

Almost surely, 2^{421402404324521} is an apocalyptic number.

It is an amenable number.

421402404324521 is a deficient number, since it is larger than the sum of its proper divisors (21156347918359).

421402404324521 is a wasteful number, since it uses less digits than its factorization.

421402404324521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066509704.

The product of its (nonzero) digits is 245760, while the sum is 38.

Adding to 421402404324521 its reverse (125423404204124), we get a palindrome (546825808528645).

The spelling of 421402404324521 in words is "four hundred twenty-one trillion, four hundred two billion, four hundred four million, three hundred twenty-four thousand, five hundred twenty-one".