21741771 has 4 divisors (see below), whose sum is σ = 28989032. Its totient is φ = 14494512.

The previous prime is 21741749. The next prime is 21741781. The reversal of 21741771 is 17714712.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21741771 - 2⁹ = 21741259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21741781) 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, 3623626 + ... + 3623631.

It is an arithmetic number, because the mean of its divisors is an integer number (7247258).

Almost surely, 2^21741771 is an apocalyptic number.

21741771 is a deficient number, since it is larger than the sum of its proper divisors (7247261).

21741771 is an equidigital number, since it uses as much as digits as its factorization.

21741771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7247260.

The product of its digits is 2744, while the sum is 30.

The square root of 21741771 is about 4662.8072016758. The cubic root of 21741771 is about 279.1033006053.

The spelling of 21741771 in words is "twenty-one million, seven hundred forty-one thousand, seven hundred seventy-one".