408100021 has 8 divisors (see below), whose sum is σ = 466531520. Its totient is φ = 349701408.

The previous prime is 408099997. The next prime is 408100039. The reversal of 408100021 is 120001804.

It is a happy number.

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

It is not a de Polignac number, because 408100021 - 2²³ = 399711413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 408099968 and 408100004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (408100321) 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, 30625 + ... + 41881.

It is an arithmetic number, because the mean of its divisors is an integer number (58316440).

Almost surely, 2^408100021 is an apocalyptic number.

It is an amenable number.

408100021 is a deficient number, since it is larger than the sum of its proper divisors (58431499).

408100021 is a wasteful number, since it uses less digits than its factorization.

408100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16443.

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 408100021 is about 20201.4856136869. The cubic root of 408100021 is about 741.7465568839.

Adding to 408100021 its reverse (120001804), we get a palindrome (528101825).

The spelling of 408100021 in words is "four hundred eight million, one hundred thousand, twenty-one".