402143020021 has 4 divisors (see below), whose sum is σ = 404364804844. Its totient is φ = 399921235200.

The previous prime is 402143020001. The next prime is 402143020031. The reversal of 402143020021 is 120020341204.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 207675249796 + 194467770225 = 455714^2 + 440985^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-402143020021 is a prime.

It is a super-2 number, since 2×402143020021² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402143020001) 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, 1110892140 + ... + 1110892501.

It is an arithmetic number, because the mean of its divisors is an integer number (101091201211).

Almost surely, 2^402143020021 is an apocalyptic number.

It is an amenable number.

402143020021 is a deficient number, since it is larger than the sum of its proper divisors (2221784823).

402143020021 is a wasteful number, since it uses less digits than its factorization.

402143020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2221784822.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 402143020021 its reverse (120020341204), we get a palindrome (522163361225).

The spelling of 402143020021 in words is "four hundred two billion, one hundred forty-three million, twenty thousand, twenty-one".