21127747 has 8 divisors (see below), whose sum is σ = 21954240. Its totient is φ = 20307840.

The previous prime is 21127727. The next prime is 21127759. The reversal of 21127747 is 74772112.

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 21127747 - 2¹⁹ = 20603459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21127727) 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, 5478 + ... + 8500.

It is an arithmetic number, because the mean of its divisors is an integer number (2744280).

Almost surely, 2^21127747 is an apocalyptic number.

21127747 is a deficient number, since it is larger than the sum of its proper divisors (826493).

21127747 is a wasteful number, since it uses less digits than its factorization.

21127747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3293.

The product of its digits is 5488, while the sum is 31.

The square root of 21127747 is about 4596.4929022027. The cubic root of 21127747 is about 276.4507224482.

Adding to 21127747 its reverse (74772112), we get a palindrome (95899859).

The spelling of 21127747 in words is "twenty-one million, one hundred twenty-seven thousand, seven hundred forty-seven".