26128055856721 has 27 divisors (see below), whose sum is σ = 32912281455003. Its totient is φ = 20672379458640.

The previous prime is 26128055856713. The next prime is 26128055856731. The reversal of 26128055856721 is 12765855082162.

It is a happy number.

The square root of 26128055856721 is 5111561.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3865097020225 + 22262958836496 = 1965985^2 + 4718364^2 .

It is not a de Polignac number, because 26128055856721 - 2³ = 26128055856713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26128055856731) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 465123966 + ... + 465180136.

Almost surely, 2^{26128055856721} is an apocalyptic number.

26128055856721 is the 5111561-st square number.

26128055856721 is the 2555781-st centered octagonal number.

It is an amenable number.

26128055856721 is a deficient number, since it is larger than the sum of its proper divisors (6784225598282).

26128055856721 is an frugal number, since it uses more digits than its factorization.

26128055856721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112382 (or 56191 counting only the distinct ones).

The product of its (nonzero) digits is 16128000, while the sum is 58.

The spelling of 26128055856721 in words is "twenty-six trillion, one hundred twenty-eight billion, fifty-five million, eight hundred fifty-six thousand, seven hundred twenty-one".