405612121 has 8 divisors (see below), whose sum is σ = 409422600. Its totient is φ = 401816448.

The previous prime is 405612113. The next prime is 405612157. The reversal of 405612121 is 121216504.

It can be written as a sum of positive squares in 4 ways, for example, as 3168400 + 402443721 = 1780^2 + 20061^2 .

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 405612121 - 2³ = 405612113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 405612092 and 405612101.

It is not an unprimeable number, because it can be changed into a prime (405612161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55725 + ... + 62581.

It is an arithmetic number, because the mean of its divisors is an integer number (51177825).

Almost surely, 2^405612121 is an apocalyptic number.

It is an amenable number.

405612121 is a deficient number, since it is larger than the sum of its proper divisors (3810479).

405612121 is a wasteful number, since it uses less digits than its factorization.

405612121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7403.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 405612121 is about 20139.8143238710. The cubic root of 405612121 is about 740.2361803948.

Adding to 405612121 its reverse (121216504), we get a palindrome (526828625).

It can be divided in two parts, 40 and 5612121, that added together give a square (5612161 = 2369²).

The spelling of 405612121 in words is "four hundred five million, six hundred twelve thousand, one hundred twenty-one".