402045021 has 12 divisors (see below), whose sum is σ = 663693472. Its totient is φ = 229739976.

The previous prime is 402045013. The next prime is 402045041. The reversal of 402045021 is 120540204.

It is not a de Polignac number, because 402045021 - 2³ = 402045013 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 402044985 and 402045003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402045001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3190771 + ... + 3190896.

Almost surely, 2^402045021 is an apocalyptic number.

It is an amenable number.

402045021 is a deficient number, since it is larger than the sum of its proper divisors (261648451).

402045021 is a wasteful number, since it uses less digits than its factorization.

402045021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6381680 (or 6381677 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 402045021 is about 20051.0603460266. The cubic root of 402045021 is about 738.0598195502.

Adding to 402045021 its reverse (120540204), we get a palindrome (522585225).

The spelling of 402045021 in words is "four hundred two million, forty-five thousand, twenty-one".