420821813 has 8 divisors (see below), whose sum is σ = 435650400. Its totient is φ = 406014448.

The previous prime is 420821801. The next prime is 420821833. The reversal of 420821813 is 318128024.

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 420821813 - 2²² = 416627509 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420821833) 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, 42470 + ... + 51432.

It is an arithmetic number, because the mean of its divisors is an integer number (54456300).

Almost surely, 2^420821813 is an apocalyptic number.

It is an amenable number.

420821813 is a deficient number, since it is larger than the sum of its proper divisors (14828587).

420821813 is a wasteful number, since it uses less digits than its factorization.

420821813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10611.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 420821813 is about 20513.9419176325. The cubic root of 420821813 is about 749.3753691113.

Adding to 420821813 its reverse (318128024), we get a palindrome (738949837).

The spelling of 420821813 in words is "four hundred twenty million, eight hundred twenty-one thousand, eight hundred thirteen".