420821420 has 12 divisors (see below), whose sum is σ = 883725024. Its totient is φ = 168328560.

The previous prime is 420821419. The next prime is 420821437. The reversal of 420821420 is 24128024.

It is a happy number.

It is a super-4 number, since 4×420821420⁴ (a number of 36 digits) contains 4444 as substring.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10520516 + ... + 10520555.

It is an arithmetic number, because the mean of its divisors is an integer number (73643752).

Almost surely, 2^420821420 is an apocalyptic number.

It is an amenable number.

420821420 is an abundant number, since it is smaller than the sum of its proper divisors (462903604).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

420821420 is a wasteful number, since it uses less digits than its factorization.

420821420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21041080 (or 21041078 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 23.

The square root of 420821420 is about 20513.9323387789. The cubic root of 420821420 is about 749.3751358339.

Adding to 420821420 its reverse (24128024), we get a palindrome (444949444).

The spelling of 420821420 in words is "four hundred twenty million, eight hundred twenty-one thousand, four hundred twenty".