920404021 has 6 divisors (see below), whose sum is σ = 977730530. Its totient is φ = 866262336.

The previous prime is 920404007. The next prime is 920404127. The reversal of 920404021 is 120404029.

It can be written as a sum of positive squares in 3 ways, for example, as 600495025 + 319908996 = 24505^2 + 17886^2 .

It is not a de Polignac number, because 920404021 - 2¹⁷ = 920272949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 920403983 and 920404001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (920404421) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1592106 + ... + 1592683.

Almost surely, 2^920404021 is an apocalyptic number.

It is an amenable number.

920404021 is a deficient number, since it is larger than the sum of its proper divisors (57326509).

920404021 is a wasteful number, since it uses less digits than its factorization.

920404021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3184823 (or 3184806 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 920404021 is about 30338.1611341228. The cubic root of 920404021 is about 972.7311772344.

The spelling of 920404021 in words is "nine hundred twenty million, four hundred four thousand, twenty-one".