21075436531 has 2 divisors, whose sum is σ = 21075436532. Its totient is φ = 21075436530.

The previous prime is 21075436489. The next prime is 21075436631. The reversal of 21075436531 is 13563457012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21075436531 - 2¹¹ = 21075434483 is a prime.

It is a super-2 number, since 2×21075436531² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21075436331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10537718265 + 10537718266.

It is an arithmetic number, because the mean of its divisors is an integer number (10537718266).

Almost surely, 2^21075436531 is an apocalyptic number.

21075436531 is a deficient number, since it is larger than the sum of its proper divisors (1).

21075436531 is an equidigital number, since it uses as much as digits as its factorization.

21075436531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 37.

The spelling of 21075436531 in words is "twenty-one billion, seventy-five million, four hundred thirty-six thousand, five hundred thirty-one".