21124242111 has 32 divisors (see below), whose sum is σ = 32788901376. Its totient is φ = 11847024000.

The previous prime is 21124242101. The next prime is 21124242121. The reversal of 21124242111 is 11124242112.

It is an interprime number because it is at equal distance from previous prime (21124242101) and next prime (21124242121).

It is not a de Polignac number, because 21124242111 - 2¹¹ = 21124240063 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124242101) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 572656 + ... + 608426.

It is an arithmetic number, because the mean of its divisors is an integer number (1024653168).

Almost surely, 2^21124242111 is an apocalyptic number.

21124242111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21124242111 is a deficient number, since it is larger than the sum of its proper divisors (11664659265).

21124242111 is a wasteful number, since it uses less digits than its factorization.

21124242111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36303.

The product of its digits is 256, while the sum is 21.

Adding to 21124242111 its reverse (11124242112), we get a palindrome (32248484223).

Subtracting from 21124242111 its reverse (11124242112), we obtain a palindrome (9999999999).

The spelling of 21124242111 in words is "twenty-one billion, one hundred twenty-four million, two hundred forty-two thousand, one hundred eleven".