21123131222001 has 16 divisors (see below), whose sum is σ = 28174985121024. Its totient is φ = 14076682819584.

The previous prime is 21123131221999. The next prime is 21123131222003. The reversal of 21123131222001 is 10022213132112.

It is an interprime number because it is at equal distance from previous prime (21123131221999) and next prime (21123131222003).

It is not a de Polignac number, because 21123131222001 - 2¹ = 21123131221999 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21123131222003) 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, 332004145 + ... + 332067761.

It is an arithmetic number, because the mean of its divisors is an integer number (1760936570064).

Almost surely, 2^{21123131222001} is an apocalyptic number.

It is an amenable number.

21123131222001 is a deficient number, since it is larger than the sum of its proper divisors (7051853899023).

21123131222001 is a wasteful number, since it uses less digits than its factorization.

21123131222001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104360.

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 21123131222001 its reverse (10022213132112), we get a palindrome (31145344354113).

The spelling of 21123131222001 in words is "twenty-one trillion, one hundred twenty-three billion, one hundred thirty-one million, two hundred twenty-two thousand, one".