26409650661 has 24 divisors (see below), whose sum is σ = 40425217560. Its totient is φ = 16584691200.

The previous prime is 26409650639. The next prime is 26409650819. The reversal of 26409650661 is 16605690462.

It can be written as a sum of positive squares in 4 ways, for example, as 70308225 + 26339342436 = 8385^2 + 162294^2 .

It is not a de Polignac number, because 26409650661 - 2²⁷ = 26275432933 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26409651661) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1223280 + ... + 1244681.

It is an arithmetic number, because the mean of its divisors is an integer number (1684384065).

Almost surely, 2^26409650661 is an apocalyptic number.

It is an amenable number.

26409650661 is a deficient number, since it is larger than the sum of its proper divisors (14015566899).

26409650661 is a wasteful number, since it uses less digits than its factorization.

26409650661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2468037 (or 2468034 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 26409650661 in words is "twenty-six billion, four hundred nine million, six hundred fifty thousand, six hundred sixty-one".