402423021 has 96 divisors (see below), whose sum is σ = 821882880. Its totient is φ = 182736000.

The previous prime is 402422947. The next prime is 402423037. The reversal of 402423021 is 120324204.

It is not a de Polignac number, because 402423021 - 2¹⁰ = 402421997 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 402422985 and 402423003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402423421) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 169996 + ... + 172346.

It is an arithmetic number, because the mean of its divisors is an integer number (8561280).

Almost surely, 2^402423021 is an apocalyptic number.

It is an amenable number.

402423021 is an abundant number, since it is smaller than the sum of its proper divisors (419459859).

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

402423021 is a wasteful number, since it uses less digits than its factorization.

402423021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2407 (or 2404 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 402423021 is about 20060.4840669412. The cubic root of 402423021 is about 738.2910533748.

Adding to 402423021 its reverse (120324204), we get a palindrome (522747225).

The spelling of 402423021 in words is "four hundred two million, four hundred twenty-three thousand, twenty-one".