21123451015131 has 8 divisors (see below), whose sum is σ = 28266278615824. Its totient is φ = 14031462045600.

The previous prime is 21123451015127. The next prime is 21123451015133. The reversal of 21123451015131 is 13151015432112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21123451015131 - 2² = 21123451015127 is a prime.

It is a super-2 number, since 2×21123451015131² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21123451015133) 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, 12709656820 + ... + 12709658481.

It is an arithmetic number, because the mean of its divisors is an integer number (3533284826978).

Almost surely, 2^{21123451015131} is an apocalyptic number.

21123451015131 is a deficient number, since it is larger than the sum of its proper divisors (7142827600693).

21123451015131 is a wasteful number, since it uses less digits than its factorization.

21123451015131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25419315581.

The product of its (nonzero) digits is 3600, while the sum is 30.

Adding to 21123451015131 its reverse (13151015432112), we get a palindrome (34274466447243).

The spelling of 21123451015131 in words is "twenty-one trillion, one hundred twenty-three billion, four hundred fifty-one million, fifteen thousand, one hundred thirty-one".