21075436631 has 2 divisors, whose sum is σ = 21075436632. Its totient is φ = 21075436630.

The previous prime is 21075436531. The next prime is 21075436643. The reversal of 21075436631 is 13663457012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21075436631 - 2³⁴ = 3895567447 is a prime.

It is a super-2 number, since 2×21075436631² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21075436661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10537718315 + 10537718316.

It is an arithmetic number, because the mean of its divisors is an integer number (10537718316).

Almost surely, 2^21075436631 is an apocalyptic number.

21075436631 is a deficient number, since it is larger than the sum of its proper divisors (1).

21075436631 is an equidigital number, since it uses as much as digits as its factorization.

21075436631 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 38.

The spelling of 21075436631 in words is "twenty-one billion, seventy-five million, four hundred thirty-six thousand, six hundred thirty-one".