405221040 has 480 divisors, whose sum is σ = 1667143296. Its totient is φ = 86261760.

The previous prime is 405221039. The next prime is 405221041. The reversal of 405221040 is 40122504.

405221040 is a `hidden beast` number, since 40 + 522 + 104 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (405221039) and next prime (405221041).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (405221041) 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 95 ways as a sum of consecutive naturals, for example, 7645654 + ... + 7645706.

Almost surely, 2^405221040 is an apocalyptic number.

405221040 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 405221040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (833571648).

405221040 is an abundant number, since it is smaller than the sum of its proper divisors (1261922256).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

405221040 is a wasteful number, since it uses less digits than its factorization.

405221040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 405221040 is about 20130.1028313320. The cubic root of 405221040 is about 739.9981981938.

Adding to 405221040 its reverse (40122504), we get a palindrome (445343544).

It can be divided in two parts, 405 and 221040, that added together give a triangular number (221445 = T₆₆₅).

The spelling of 405221040 in words is "four hundred five million, two hundred twenty-one thousand, forty".