20447678 has 4 divisors (see below), whose sum is σ = 30671520. Its totient is φ = 10223838.

The previous prime is 20447677. The next prime is 20447681. The reversal of 20447678 is 87674402.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20447671) 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, 5111918 + ... + 5111921.

It is an arithmetic number, because the mean of its divisors is an integer number (7667880).

Almost surely, 2^20447678 is an apocalyptic number.

20447678 is a deficient number, since it is larger than the sum of its proper divisors (10223842).

20447678 is a wasteful number, since it uses less digits than its factorization.

20447678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10223841.

The product of its (nonzero) digits is 75264, while the sum is 38.

The square root of 20447678 is about 4521.9108792633. The cubic root of 20447678 is about 273.4521438013.

The spelling of 20447678 in words is "twenty million, four hundred forty-seven thousand, six hundred seventy-eight".