20782487 has 4 divisors (see below), whose sum is σ = 22671816. Its totient is φ = 18893160.

The previous prime is 20782477. The next prime is 20782499. The reversal of 20782487 is 78428702.

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

It is not a de Polignac number, because 20782487 - 2⁸ = 20782231 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20782487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20782417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 944648 + ... + 944669.

It is an arithmetic number, because the mean of its divisors is an integer number (5667954).

Almost surely, 2^20782487 is an apocalyptic number.

20782487 is a deficient number, since it is larger than the sum of its proper divisors (1889329).

20782487 is a wasteful number, since it uses less digits than its factorization.

20782487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1889328.

The product of its (nonzero) digits is 50176, while the sum is 38.

The square root of 20782487 is about 4558.7813064458. The cubic root of 20782487 is about 274.9365671876.

The spelling of 20782487 in words is "twenty million, seven hundred eighty-two thousand, four hundred eighty-seven".