21147677 has 8 divisors (see below), whose sum is σ = 22938552. Its totient is φ = 19417600.

The previous prime is 21147671. The next prime is 21147713. The reversal of 21147677 is 77674112.

It can be written as a sum of positive squares in 4 ways, for example, as 116281 + 21031396 = 341^2 + 4586^2 .

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

It is not a de Polignac number, because 21147677 - 2⁴ = 21147661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21147671) 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, 14474 + ... + 15867.

It is an arithmetic number, because the mean of its divisors is an integer number (2867319).

Almost surely, 2^21147677 is an apocalyptic number.

It is an amenable number.

21147677 is a deficient number, since it is larger than the sum of its proper divisors (1790875).

21147677 is a wasteful number, since it uses less digits than its factorization.

21147677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30399.

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

The square root of 21147677 is about 4598.6603484058. The cubic root of 21147677 is about 276.5376213079.

The spelling of 21147677 in words is "twenty-one million, one hundred forty-seven thousand, six hundred seventy-seven".