20780587 has 8 divisors (see below), whose sum is σ = 21105504. Its totient is φ = 20458368.

The previous prime is 20780581. The next prime is 20780657. The reversal of 20780587 is 78508702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20780587 - 2¹⁵ = 20747819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20780581) 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 7 ways as a sum of consecutive naturals, for example, 19018 + ... + 20080.

It is an arithmetic number, because the mean of its divisors is an integer number (2638188).

Almost surely, 2^20780587 is an apocalyptic number.

20780587 is a deficient number, since it is larger than the sum of its proper divisors (324917).

20780587 is a wasteful number, since it uses less digits than its factorization.

20780587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1349.

The product of its (nonzero) digits is 31360, while the sum is 37.

The square root of 20780587 is about 4558.5729126559. The cubic root of 20780587 is about 274.9281884118.

The spelling of 20780587 in words is "twenty million, seven hundred eighty thousand, five hundred eighty-seven".