20678540 has 12 divisors (see below), whose sum is σ = 43424976. Its totient is φ = 8271408.

The previous prime is 20678531. The next prime is 20678549. The reversal of 20678540 is 4587602.

It is an interprime number because it is at equal distance from previous prime (20678531) and next prime (20678549).

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 20678497 and 20678506.

It is not an unprimeable number, because it can be changed into a prime (20678549) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 516944 + ... + 516983.

It is an arithmetic number, because the mean of its divisors is an integer number (3618748).

Almost surely, 2^20678540 is an apocalyptic number.

20678540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20678540 is an abundant number, since it is smaller than the sum of its proper divisors (22746436).

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

20678540 is a wasteful number, since it uses less digits than its factorization.

20678540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1033936 (or 1033934 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 20678540 is about 4547.3662707110. The cubic root of 20678540 is about 274.4774208012.

The spelling of 20678540 in words is "twenty million, six hundred seventy-eight thousand, five hundred forty".