405881280 has 280 divisors, whose sum is σ = 1650784608. Its totient is φ = 92731392.

The previous prime is 405881279. The next prime is 405881291. The reversal of 405881280 is 82188504.

It is a tau number, because it is divible by the number of its divisors (280).

It is a super-2 number, since 2×405881280² = 329479226908876800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 180322 + ... + 182558.

Almost surely, 2^405881280 is an apocalyptic number.

405881280 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 405881280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (825392304).

405881280 is an abundant number, since it is smaller than the sum of its proper divisors (1244903328).

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

405881280 is a wasteful number, since it uses less digits than its factorization.

405881280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2273 (or 2254 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 36.

The square root of 405881280 is about 20146.4954768813. The cubic root of 405881280 is about 740.3998812679.

The spelling of 405881280 in words is "four hundred five million, eight hundred eighty-one thousand, two hundred eighty".