21270571 has 4 divisors (see below), whose sum is σ = 24309232. Its totient is φ = 18231912.

The previous prime is 21270569. The next prime is 21270583. The reversal of 21270571 is 17507212.

It is a happy number.

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 21270571 - 2¹ = 21270569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21270511) 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, 1519320 + ... + 1519333.

It is an arithmetic number, because the mean of its divisors is an integer number (6077308).

Almost surely, 2^21270571 is an apocalyptic number.

21270571 is a deficient number, since it is larger than the sum of its proper divisors (3038661).

21270571 is an equidigital number, since it uses as much as digits as its factorization.

21270571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3038660.

The product of its (nonzero) digits is 980, while the sum is 25.

The square root of 21270571 is about 4612.0029271456. The cubic root of 21270571 is about 277.0722615107.

Adding to 21270571 its reverse (17507212), we get a palindrome (38777783).

The spelling of 21270571 in words is "twenty-one million, two hundred seventy thousand, five hundred seventy-one".