21677147 has 4 divisors (see below), whose sum is σ = 21815376. Its totient is φ = 21538920.

The previous prime is 21677141. The next prime is 21677167. The reversal of 21677147 is 74177612.

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

It is a cyclic number.

It is not a de Polignac number, because 21677147 - 2²⁴ = 4899931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21677141) 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, 68879 + ... + 69192.

It is an arithmetic number, because the mean of its divisors is an integer number (5453844).

Almost surely, 2^21677147 is an apocalyptic number.

21677147 is a deficient number, since it is larger than the sum of its proper divisors (138229).

21677147 is a wasteful number, since it uses less digits than its factorization.

21677147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138228.

The product of its digits is 16464, while the sum is 35.

The square root of 21677147 is about 4655.8723135413. The cubic root of 21677147 is about 278.8264959274.

The spelling of 21677147 in words is "twenty-one million, six hundred seventy-seven thousand, one hundred forty-seven".