405109920 has 96 divisors (see below), whose sum is σ = 1303319808. Its totient is φ = 105724928.

The previous prime is 405109919. The next prime is 405109921. The reversal of 405109920 is 29901504.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (405109919) and next prime (405109921).

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×405109920² = 328228094564812800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (405109921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13582 + ... + 31538.

It is an arithmetic number, because the mean of its divisors is an integer number (13576248).

Almost surely, 2^405109920 is an apocalyptic number.

405109920 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 405109920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (651659904).

405109920 is an abundant number, since it is smaller than the sum of its proper divisors (898209888).

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

405109920 is a wasteful number, since it uses less digits than its factorization.

405109920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18022 (or 18014 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 405109920 is about 20127.3425965774. The cubic root of 405109920 is about 739.9305510670.

The spelling of 405109920 in words is "four hundred five million, one hundred nine thousand, nine hundred twenty".