21077187 has 8 divisors (see below), whose sum is σ = 28176720. Its totient is φ = 14014560.

The previous prime is 21077183. The next prime is 21077191. The reversal of 21077187 is 78177012.

It is an interprime number because it is at equal distance from previous prime (21077183) and next prime (21077191).

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

It is not a de Polignac number, because 21077187 - 2² = 21077183 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21077183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7864 + ... + 10197.

It is an arithmetic number, because the mean of its divisors is an integer number (3522090).

Almost surely, 2^21077187 is an apocalyptic number.

21077187 is a deficient number, since it is larger than the sum of its proper divisors (7099533).

21077187 is a wasteful number, since it uses less digits than its factorization.

21077187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18453.

The product of its (nonzero) digits is 5488, while the sum is 33.

The square root of 21077187 is about 4590.9897625675. The cubic root of 21077187 is about 276.2300251044.

The spelling of 21077187 in words is "twenty-one million, seventy-seven thousand, one hundred eighty-seven".