20887491 has 8 divisors (see below), whose sum is σ = 28529424. Its totient is φ = 13585280.

The previous prime is 20887483. The next prime is 20887541. The reversal of 20887491 is 19478802.

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 20887491 - 2³ = 20887483 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20887891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84786 + ... + 85031.

It is an arithmetic number, because the mean of its divisors is an integer number (3566178).

Almost surely, 2^20887491 is an apocalyptic number.

20887491 is a deficient number, since it is larger than the sum of its proper divisors (7641933).

20887491 is a wasteful number, since it uses less digits than its factorization.

20887491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169861.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 20887491 is about 4570.2834704206. The cubic root of 20887491 is about 275.3988306653.

The spelling of 20887491 in words is "twenty million, eight hundred eighty-seven thousand, four hundred ninety-one".