26610661421 has 2 divisors, whose sum is σ = 26610661422. Its totient is φ = 26610661420.

The previous prime is 26610661397. The next prime is 26610661477. The reversal of 26610661421 is 12416601662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26312408521 + 298252900 = 162211^2 + 17270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26610661421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26610660421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13305330710 + 13305330711.

It is an arithmetic number, because the mean of its divisors is an integer number (13305330711).

Almost surely, 2^26610661421 is an apocalyptic number.

It is an amenable number.

26610661421 is a deficient number, since it is larger than the sum of its proper divisors (1).

26610661421 is an equidigital number, since it uses as much as digits as its factorization.

26610661421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 35.

The spelling of 26610661421 in words is "twenty-six billion, six hundred ten million, six hundred sixty-one thousand, four hundred twenty-one".