20717678 has 4 divisors (see below), whose sum is σ = 31076520. Its totient is φ = 10358838.

The previous prime is 20717677. The next prime is 20717693. The reversal of 20717678 is 87671702.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20717677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5179418 + ... + 5179421.

It is an arithmetic number, because the mean of its divisors is an integer number (7769130).

Almost surely, 2^20717678 is an apocalyptic number.

20717678 is a deficient number, since it is larger than the sum of its proper divisors (10358842).

20717678 is a wasteful number, since it uses less digits than its factorization.

20717678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10358841.

The product of its (nonzero) digits is 32928, while the sum is 38.

The square root of 20717678 is about 4551.6676064933. The cubic root of 20717678 is about 274.6504782643.

The spelling of 20717678 in words is "twenty million, seven hundred seventeen thousand, six hundred seventy-eight".