21113771 has 8 divisors (see below), whose sum is σ = 24219360. Its totient is φ = 18030528.

The previous prime is 21113723. The next prime is 21113773. The reversal of 21113771 is 17731112.

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 21113771 - 2⁶ = 21113707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21113773) 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, 3506 + ... + 7383.

It is an arithmetic number, because the mean of its divisors is an integer number (3027420).

Almost surely, 2^21113771 is an apocalyptic number.

21113771 is a deficient number, since it is larger than the sum of its proper divisors (3105589).

21113771 is a wasteful number, since it uses less digits than its factorization.

21113771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11173.

The product of its digits is 294, while the sum is 23.

The square root of 21113771 is about 4594.9723611791. The cubic root of 21113771 is about 276.3897516381.

Adding to 21113771 its reverse (17731112), we get a palindrome (38844883).

The spelling of 21113771 in words is "twenty-one million, one hundred thirteen thousand, seven hundred seventy-one".