20400084 has 36 divisors (see below), whose sum is σ = 51804480. Its totient is φ = 6768720.

The previous prime is 20400059. The next prime is 20400089. The reversal of 20400084 is 48000402.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400089) 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, 7419 + ... + 9789.

Almost surely, 2^20400084 is an apocalyptic number.

It is an amenable number.

20400084 is an abundant number, since it is smaller than the sum of its proper divisors (31404396).

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

20400084 is a wasteful number, since it uses less digits than its factorization.

20400084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2620 (or 2615 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 20400084 is about 4516.6452152012. The cubic root of 20400084 is about 273.2398166435.

Adding to 20400084 its reverse (48000402), we get a palindrome (68400486).

The spelling of 20400084 in words is "twenty million, four hundred thousand, eighty-four".