20478140 has 24 divisors (see below), whose sum is σ = 43817760. Its totient is φ = 8036288.

The previous prime is 20478121. The next prime is 20478173. The reversal of 20478140 is 4187402.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8600 + ... + 10719.

It is an arithmetic number, because the mean of its divisors is an integer number (1825740).

Almost surely, 2^20478140 is an apocalyptic number.

20478140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20478140 is an abundant number, since it is smaller than the sum of its proper divisors (23339620).

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

20478140 is a wasteful number, since it uses less digits than its factorization.

20478140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19381 (or 19379 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 20478140 is about 4525.2778920195. The cubic root of 20478140 is about 273.5878685215.

The spelling of 20478140 in words is "twenty million, four hundred seventy-eight thousand, one hundred forty".