405145221 has 12 divisors (see below), whose sum is σ = 584944128. Its totient is φ = 249319824.

The previous prime is 405145201. The next prime is 405145267. The reversal of 405145221 is 122541504.

It is not a de Polignac number, because 405145221 - 2⁷ = 405145093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 405145191 and 405145200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405145201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 399045 + ... + 400058.

It is an arithmetic number, because the mean of its divisors is an integer number (48745344).

Almost surely, 2^405145221 is an apocalyptic number.

It is an amenable number.

405145221 is a deficient number, since it is larger than the sum of its proper divisors (179798907).

405145221 is a wasteful number, since it uses less digits than its factorization.

405145221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 799132 (or 799119 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 405145221 is about 20128.2195188745. The cubic root of 405145221 is about 739.9520427894.

Adding to 405145221 its reverse (122541504), we get a palindrome (527686725).

The spelling of 405145221 in words is "four hundred five million, one hundred forty-five thousand, two hundred twenty-one".