26521630561 has 8 divisors (see below), whose sum is σ = 26871150600. Its totient is φ = 26173255680.

The previous prime is 26521630559. The next prime is 26521630573. The reversal of 26521630561 is 16503612562.

It can be written as a sum of positive squares in 4 ways, for example, as 719312400 + 25802318161 = 26820^2 + 160631^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 26521630561 - 2¹ = 26521630559 is a prime.

It is a super-2 number, since 2×26521630561² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 26521630561.

It is not an unprimeable number, because it can be changed into a prime (26521630591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 239616 + ... + 332353.

It is an arithmetic number, because the mean of its divisors is an integer number (3358893825).

Almost surely, 2^26521630561 is an apocalyptic number.

It is an amenable number.

26521630561 is a deficient number, since it is larger than the sum of its proper divisors (349520039).

26521630561 is an equidigital number, since it uses as much as digits as its factorization.

26521630561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 572579.

The product of its (nonzero) digits is 64800, while the sum is 37.

The spelling of 26521630561 in words is "twenty-six billion, five hundred twenty-one million, six hundred thirty thousand, five hundred sixty-one".