421012021 has 6 divisors (see below), whose sum is σ = 447234530. Its totient is φ = 396246336.

The previous prime is 421012001. The next prime is 421012027. The reversal of 421012021 is 120210124.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 101103025 + 319908996 = 10055^2 + 17886^2 .

It is not a de Polignac number, because 421012021 - 2⁵ = 421011989 is a prime.

It is a super-2 number, since 2×421012021² = 354502243653008882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 421011992 and 421012010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421012027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 728106 + ... + 728683.

Almost surely, 2^421012021 is an apocalyptic number.

It is an amenable number.

421012021 is a deficient number, since it is larger than the sum of its proper divisors (26222509).

421012021 is a wasteful number, since it uses less digits than its factorization.

421012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1456823 (or 1456806 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 421012021 is about 20518.5774604381. The cubic root of 421012021 is about 749.4882559405.

Adding to 421012021 its reverse (120210124), we get a palindrome (541222145).

The spelling of 421012021 in words is "four hundred twenty-one million, twelve thousand, twenty-one".