21275771 has 8 divisors (see below), whose sum is σ = 23271600. Its totient is φ = 19290240.

The previous prime is 21275747. The next prime is 21275809. The reversal of 21275771 is 17757212.

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 21275771 - 2⁶ = 21275707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21275711) 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, 2135 + ... + 6863.

It is an arithmetic number, because the mean of its divisors is an integer number (2908950).

Almost surely, 2^21275771 is an apocalyptic number.

21275771 is a deficient number, since it is larger than the sum of its proper divisors (1995829).

21275771 is a wasteful number, since it uses less digits than its factorization.

21275771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5149.

The product of its digits is 6860, while the sum is 32.

The square root of 21275771 is about 4612.5666390850. The cubic root of 21275771 is about 277.0948382180.

The spelling of 21275771 in words is "twenty-one million, two hundred seventy-five thousand, seven hundred seventy-one".