21037507943 has 2 divisors, whose sum is σ = 21037507944. Its totient is φ = 21037507942.

The previous prime is 21037507913. The next prime is 21037507969. The reversal of 21037507943 is 34970573012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21037507943 - 2¹² = 21037503847 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21037507943.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21037507913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10518753971 + 10518753972.

It is an arithmetic number, because the mean of its divisors is an integer number (10518753972).

Almost surely, 2^21037507943 is an apocalyptic number.

21037507943 is a deficient number, since it is larger than the sum of its proper divisors (1).

21037507943 is an equidigital number, since it uses as much as digits as its factorization.

21037507943 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 158760, while the sum is 41.

The spelling of 21037507943 in words is "twenty-one billion, thirty-seven million, five hundred seven thousand, nine hundred forty-three".