20406984 has 32 divisors (see below), whose sum is σ = 54942720. Its totient is φ = 6278976.

The previous prime is 20406973. The next prime is 20406989. The reversal of 20406984 is 48960402.

It is not an unprimeable number, because it can be changed into a prime (20406989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32392 + ... + 33015.

It is an arithmetic number, because the mean of its divisors is an integer number (1716960).

Almost surely, 2^20406984 is an apocalyptic number.

20406984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20406984 is an abundant number, since it is smaller than the sum of its proper divisors (34535736).

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

20406984 is a wasteful number, since it uses less digits than its factorization.

20406984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65429 (or 65425 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 20406984 is about 4517.4089918890. The cubic root of 20406984 is about 273.2706194939.

The spelling of 20406984 in words is "twenty million, four hundred six thousand, nine hundred eighty-four".