402100213400021 has 8 divisors (see below), whose sum is σ = 425754343943640. Its totient is φ = 378446213613568.

The previous prime is 402100213399993. The next prime is 402100213400051. The reversal of 402100213400021 is 120004312001204.

It can be written as a sum of positive squares in 4 ways, for example, as 43192682428996 + 358907530971025 = 6572114^2 + 18944855^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 402100213400021 - 2²⁶ = 402100146291157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 402100213399966 and 402100213400002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402100213400051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26322626 + ... + 38692131.

It is an arithmetic number, because the mean of its divisors is an integer number (53219292992955).

Almost surely, 2^{402100213400021} is an apocalyptic number.

It is an amenable number.

402100213400021 is a deficient number, since it is larger than the sum of its proper divisors (23654130543619).

402100213400021 is a wasteful number, since it uses less digits than its factorization.

402100213400021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65378583.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 402100213400021 its reverse (120004312001204), we get a palindrome (522104525401225).

The spelling of 402100213400021 in words is "four hundred two trillion, one hundred billion, two hundred thirteen million, four hundred thousand, twenty-one".