20887478 has 4 divisors (see below), whose sum is σ = 31331220. Its totient is φ = 10443738.

The previous prime is 20887457. The next prime is 20887483. The reversal of 20887478 is 87478802.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5221868 + ... + 5221871.

It is an arithmetic number, because the mean of its divisors is an integer number (7832805).

Almost surely, 2^20887478 is an apocalyptic number.

20887478 is a deficient number, since it is larger than the sum of its proper divisors (10443742).

20887478 is a wasteful number, since it uses less digits than its factorization.

20887478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10443741.

The product of its (nonzero) digits is 200704, while the sum is 44.

The square root of 20887478 is about 4570.2820481891. The cubic root of 20887478 is about 275.3987735309.

The spelling of 20887478 in words is "twenty million, eight hundred eighty-seven thousand, four hundred seventy-eight".