21031122025531 has 2 divisors, whose sum is σ = 21031122025532. Its totient is φ = 21031122025530.

The previous prime is 21031122025517. The next prime is 21031122025547. The reversal of 21031122025531 is 13552022113012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21031122025531 - 2³³ = 21022532090939 is a prime.

It is a super-2 number, since 2×21031122025531² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21031122025531.

It is not a weakly prime, because it can be changed into another prime (21031122022531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515561012765 + 10515561012766.

It is an arithmetic number, because the mean of its divisors is an integer number (10515561012766).

Almost surely, 2^{21031122025531} is an apocalyptic number.

21031122025531 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031122025531 is an equidigital number, since it uses as much as digits as its factorization.

21031122025531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 28.

Adding to 21031122025531 its reverse (13552022113012), we get a palindrome (34583144138543).

The spelling of 21031122025531 in words is "twenty-one trillion, thirty-one billion, one hundred twenty-two million, twenty-five thousand, five hundred thirty-one".