26021660721 has 8 divisors (see below), whose sum is σ = 39652054464. Its totient is φ = 14869520400.

The previous prime is 26021660713. The next prime is 26021660761. The reversal of 26021660721 is 12706612062.

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

It is not a de Polignac number, because 26021660721 - 2³ = 26021660713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (26021660761) 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, 619563330 + ... + 619563371.

It is an arithmetic number, because the mean of its divisors is an integer number (4956506808).

Almost surely, 2^26021660721 is an apocalyptic number.

26021660721 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

26021660721 is a deficient number, since it is larger than the sum of its proper divisors (13630393743).

26021660721 is a wasteful number, since it uses less digits than its factorization.

26021660721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1239126711.

The product of its (nonzero) digits is 12096, while the sum is 33.

The spelling of 26021660721 in words is "twenty-six billion, twenty-one million, six hundred sixty thousand, seven hundred twenty-one".