406204237821 has 4 divisors (see below), whose sum is σ = 541605650432. Its totient is φ = 270802825212.

The previous prime is 406204237811. The next prime is 406204237843. The reversal of 406204237821 is 128732402604.

It is a happy number.

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 not a de Polignac number, because 406204237821 - 2⁶ = 406204237757 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 406204237821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (406204237801) 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, 67700706301 + ... + 67700706306.

It is an arithmetic number, because the mean of its divisors is an integer number (135401412608).

Almost surely, 2^406204237821 is an apocalyptic number.

It is an amenable number.

406204237821 is a deficient number, since it is larger than the sum of its proper divisors (135401412611).

406204237821 is a wasteful number, since it uses less digits than its factorization.

406204237821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135401412610.

The product of its (nonzero) digits is 129024, while the sum is 39.

The spelling of 406204237821 in words is "four hundred six billion, two hundred four million, two hundred thirty-seven thousand, eight hundred twenty-one".