21111022129 has 4 divisors (see below), whose sum is σ = 21601976176. Its totient is φ = 20620068084.

The previous prime is 21111022117. The next prime is 21111022133. The reversal of 21111022129 is 92122011112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21111022129 - 2²³ = 21102633521 is a prime.

It is a super-2 number, since 2×21111022129² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111020129) 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, 245476959 + ... + 245477044.

It is an arithmetic number, because the mean of its divisors is an integer number (5400494044).

Almost surely, 2^21111022129 is an apocalyptic number.

It is an amenable number.

21111022129 is a deficient number, since it is larger than the sum of its proper divisors (490954047).

21111022129 is an equidigital number, since it uses as much as digits as its factorization.

21111022129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490954046.

The product of its (nonzero) digits is 144, while the sum is 22.

The spelling of 21111022129 in words is "twenty-one billion, one hundred eleven million, twenty-two thousand, one hundred twenty-nine".