420821391 has 8 divisors (see below), whose sum is σ = 561192624. Its totient is φ = 280498880.

The previous prime is 420821389. The next prime is 420821413. The reversal of 420821391 is 193128024.

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 420821391 - 2¹ = 420821389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420821321) 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, 20515 + ... + 35531.

It is an arithmetic number, because the mean of its divisors is an integer number (70149078).

Almost surely, 2^420821391 is an apocalyptic number.

420821391 is a deficient number, since it is larger than the sum of its proper divisors (140371233).

420821391 is a wasteful number, since it uses less digits than its factorization.

420821391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24361.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 420821391 is about 20513.9316319422. The cubic root of 420821391 is about 749.3751186201.

The spelling of 420821391 in words is "four hundred twenty million, eight hundred twenty-one thousand, three hundred ninety-one".