21731064529 has 2 divisors, whose sum is σ = 21731064530. Its totient is φ = 21731064528.

The previous prime is 21731064517. The next prime is 21731064577. The reversal of 21731064529 is 92546013712.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13105670400 + 8625394129 = 114480^2 + 92873^2 .

It is a cyclic number.

It is not a de Polignac number, because 21731064529 - 2¹³ = 21731056337 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21731064491 and 21731064500.

It is not a weakly prime, because it can be changed into another prime (21731064029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10865532264 + 10865532265.

It is an arithmetic number, because the mean of its divisors is an integer number (10865532265).

Almost surely, 2^21731064529 is an apocalyptic number.

It is an amenable number.

21731064529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21731064529 is an equidigital number, since it uses as much as digits as its factorization.

21731064529 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 40.

The spelling of 21731064529 in words is "twenty-one billion, seven hundred thirty-one million, sixty-four thousand, five hundred twenty-nine".