21311010331123 has 4 divisors (see below), whose sum is σ = 21312085632760. Its totient is φ = 21309935029488.

The previous prime is 21311010331049. The next prime is 21311010331201. The reversal of 21311010331123 is 32113301011312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21311010331123 is a prime.

It is a super-2 number, since 2×21311010331123² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21311010331094 and 21311010331103.

It is not an unprimeable number, because it can be changed into a prime (21311010301123) 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, 537621090 + ... + 537660727.

It is an arithmetic number, because the mean of its divisors is an integer number (5328021408190).

Almost surely, 2^{21311010331123} is an apocalyptic number.

21311010331123 is a deficient number, since it is larger than the sum of its proper divisors (1075301637).

21311010331123 is a wasteful number, since it uses less digits than its factorization.

21311010331123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1075301636.

The product of its (nonzero) digits is 324, while the sum is 22.

Adding to 21311010331123 its reverse (32113301011312), we get a palindrome (53424311342435).

The spelling of 21311010331123 in words is "twenty-one trillion, three hundred eleven billion, ten million, three hundred thirty-one thousand, one hundred twenty-three".