420043021 has 8 divisors (see below), whose sum is σ = 446697720. Its totient is φ = 393604608.

The previous prime is 420043003. The next prime is 420043027. The reversal of 420043021 is 120340024.

It can be written as a sum of positive squares in 4 ways, for example, as 202037796 + 218005225 = 14214^2 + 14765^2 .

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-420043021 is a prime.

It is a super-2 number, since 2×420043021² = 352872278981612882, 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 = 420042986 and 420043004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420043027) 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, 50056 + ... + 57841.

It is an arithmetic number, because the mean of its divisors is an integer number (55837215).

Almost surely, 2^420043021 is an apocalyptic number.

It is an amenable number.

420043021 is a deficient number, since it is larger than the sum of its proper divisors (26654699).

420043021 is a wasteful number, since it uses less digits than its factorization.

420043021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108143.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 420043021 is about 20494.9511099685. The cubic root of 420043021 is about 748.9128075932.

Adding to 420043021 its reverse (120340024), we get a palindrome (540383045).

The spelling of 420043021 in words is "four hundred twenty million, forty-three thousand, twenty-one".