21496537507 has 4 divisors (see below), whose sum is σ = 21497471640. Its totient is φ = 21495603376.

The previous prime is 21496537459. The next prime is 21496537529. The reversal of 21496537507 is 70573569412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21496537507 - 2¹⁹ = 21496013219 is a prime.

It is a super-2 number, since 2×21496537507² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21496547507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 431653 + ... + 478870.

It is an arithmetic number, because the mean of its divisors is an integer number (5374367910).

Almost surely, 2^21496537507 is an apocalyptic number.

21496537507 is a deficient number, since it is larger than the sum of its proper divisors (934133).

21496537507 is an equidigital number, since it uses as much as digits as its factorization.

21496537507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934132.

The product of its (nonzero) digits is 1587600, while the sum is 49.

The spelling of 21496537507 in words is "twenty-one billion, four hundred ninety-six million, five hundred thirty-seven thousand, five hundred seven".