21700271 has 4 divisors (see below), whose sum is σ = 21820344. Its totient is φ = 21580200.

The previous prime is 21700253. The next prime is 21700291. The reversal of 21700271 is 17200712.

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 21700271 - 2¹⁰ = 21699247 is a prime.

It is a super-2 number, since 2×21700271² = 941803522946882, which contains 22 as substring.

It is a Duffinian number.

21700271 is a modest number, since divided by 271 gives 217 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21700291) 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, 59765 + ... + 60126.

It is an arithmetic number, because the mean of its divisors is an integer number (5455086).

Almost surely, 2^21700271 is an apocalyptic number.

21700271 is a deficient number, since it is larger than the sum of its proper divisors (120073).

21700271 is a wasteful number, since it uses less digits than its factorization.

21700271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120072.

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 21700271 is about 4658.3549671531. The cubic root of 21700271 is about 278.9256063347.

Adding to 21700271 its reverse (17200712), we get a palindrome (38900983).

The spelling of 21700271 in words is "twenty-one million, seven hundred thousand, two hundred seventy-one".