20960987 has 4 divisors (see below), whose sum is σ = 20987280. Its totient is φ = 20934696.

The previous prime is 20960959. The next prime is 20960999. The reversal of 20960987 is 78906902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78906902 = 2 ⋅39453451.

It is a cyclic number.

It is not a de Polignac number, because 20960987 - 2⁶ = 20960923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20960957) 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, 11912 + ... + 13557.

It is an arithmetic number, because the mean of its divisors is an integer number (5246820).

Almost surely, 2^20960987 is an apocalyptic number.

20960987 is a deficient number, since it is larger than the sum of its proper divisors (26293).

20960987 is an equidigital number, since it uses as much as digits as its factorization.

20960987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26292.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 20960987 is about 4578.3170488729. The cubic root of 20960987 is about 275.7214642564.

The spelling of 20960987 in words is "twenty million, nine hundred sixty thousand, nine hundred eighty-seven".