21123131230191 has 16 divisors (see below), whose sum is σ = 28244514096000. Its totient is φ = 14041965723360.

The previous prime is 21123131230171. The next prime is 21123131230199. The reversal of 21123131230191 is 19103213132112.

It is not a de Polignac number, because 21123131230191 - 2¹³ = 21123131221999 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123131230199) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4205925 + ... + 7741838.

It is an arithmetic number, because the mean of its divisors is an integer number (1765282131000).

Almost surely, 2^{21123131230191} is an apocalyptic number.

21123131230191 is a deficient number, since it is larger than the sum of its proper divisors (7121382865809).

21123131230191 is a wasteful number, since it uses less digits than its factorization.

21123131230191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11949446.

The product of its (nonzero) digits is 1944, while the sum is 30.

The spelling of 21123131230191 in words is "twenty-one trillion, one hundred twenty-three billion, one hundred thirty-one million, two hundred thirty thousand, one hundred ninety-one".