21064032537 has 4 divisors (see below), whose sum is σ = 28085376720. Its totient is φ = 14042688356.

The previous prime is 21064032533. The next prime is 21064032541. The reversal of 21064032537 is 73523046012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (21064032533) and next prime (21064032541).

It is a cyclic number.

It is not a de Polignac number, because 21064032537 - 2² = 21064032533 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21064032498 and 21064032507.

It is not an unprimeable number, because it can be changed into a prime (21064032533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3510672087 + ... + 3510672092.

It is an arithmetic number, because the mean of its divisors is an integer number (7021344180).

Almost surely, 2^21064032537 is an apocalyptic number.

It is an amenable number.

21064032537 is a deficient number, since it is larger than the sum of its proper divisors (7021344183).

21064032537 is an equidigital number, since it uses as much as digits as its factorization.

21064032537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7021344182.

The product of its (nonzero) digits is 30240, while the sum is 33.

Adding to 21064032537 its reverse (73523046012), we get a palindrome (94587078549).

The spelling of 21064032537 in words is "twenty-one billion, sixty-four million, thirty-two thousand, five hundred thirty-seven".