402143021 has 4 divisors (see below), whose sum is σ = 459592032. Its totient is φ = 344694012.

The previous prime is 402142991. The next prime is 402143023. The reversal of 402143021 is 120341204.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 402143021 - 2⁶ = 402142957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402143023) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28724495 + ... + 28724508.

It is an arithmetic number, because the mean of its divisors is an integer number (114898008).

Almost surely, 2^402143021 is an apocalyptic number.

It is an amenable number.

402143021 is a deficient number, since it is larger than the sum of its proper divisors (57449011).

402143021 is an equidigital number, since it uses as much as digits as its factorization.

402143021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57449010.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 402143021 is about 20053.5039581615. The cubic root of 402143021 is about 738.1197829725.

Adding to 402143021 its reverse (120341204), we get a palindrome (522484225).

The spelling of 402143021 in words is "four hundred two million, one hundred forty-three thousand, twenty-one".