21755071 has 8 divisors (see below), whose sum is σ = 23693040. Its totient is φ = 19854912.

The previous prime is 21755021. The next prime is 21755077. The reversal of 21755071 is 17055712.

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 21755071 - 2¹¹ = 21753023 is a prime.

It is a super-2 number, since 2×21755071² = 946566228430082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21755077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8245 + ... + 10558.

It is an arithmetic number, because the mean of its divisors is an integer number (2961630).

Almost surely, 2^21755071 is an apocalyptic number.

21755071 is a deficient number, since it is larger than the sum of its proper divisors (1937969).

21755071 is a wasteful number, since it uses less digits than its factorization.

21755071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18905.

The product of its (nonzero) digits is 2450, while the sum is 28.

The square root of 21755071 is about 4664.2331631255. The cubic root of 21755071 is about 279.1602005581.

The spelling of 21755071 in words is "twenty-one million, seven hundred fifty-five thousand, seventy-one".