421355521 has 8 divisors (see below), whose sum is σ = 429125760. Its totient is φ = 413606352.

The previous prime is 421355509. The next prime is 421355531. The reversal of 421355521 is 125553124.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421355521 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 421355521.

It is not an unprimeable number, because it can be changed into a prime (421355531) 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, 38376 + ... + 48118.

It is an arithmetic number, because the mean of its divisors is an integer number (53640720).

Almost surely, 2^421355521 is an apocalyptic number.

It is an amenable number.

421355521 is a deficient number, since it is larger than the sum of its proper divisors (7770239).

421355521 is an equidigital number, since it uses as much as digits as its factorization.

421355521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10535.

The product of its digits is 6000, while the sum is 28.

The square root of 421355521 is about 20526.9462171069. The cubic root of 421355521 is about 749.6920341526.

The spelling of 421355521 in words is "four hundred twenty-one million, three hundred fifty-five thousand, five hundred twenty-one".