20181408 has 96 divisors (see below), whose sum is σ = 57972096. Its totient is φ = 6110208.

The previous prime is 20181353. The next prime is 20181437. The reversal of 20181408 is 80418102.

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

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 128466 + ... + 128622.

It is an arithmetic number, because the mean of its divisors is an integer number (603876).

Almost surely, 2^20181408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20181408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28986048).

20181408 is an abundant number, since it is smaller than the sum of its proper divisors (37790688).

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

20181408 is a wasteful number, since it uses less digits than its factorization.

20181408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286 (or 278 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 20181408 is about 4492.3722018551. The cubic root of 20181408 is about 272.2599878621.

The spelling of 20181408 in words is "twenty million, one hundred eighty-one thousand, four hundred eight".