26721681 has 8 divisors (see below), whose sum is σ = 40718784. Its totient is φ = 15269520.

The previous prime is 26721679. The next prime is 26721691. The reversal of 26721681 is 18612762.

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

It is not a de Polignac number, because 26721681 - 2¹ = 26721679 is a prime.

It is a super-2 number, since 2×26721681² = 1428096470931522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (26721641) 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, 636210 + ... + 636251.

It is an arithmetic number, because the mean of its divisors is an integer number (5089848).

Almost surely, 2^26721681 is an apocalyptic number.

26721681 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

26721681 is a deficient number, since it is larger than the sum of its proper divisors (13997103).

26721681 is a wasteful number, since it uses less digits than its factorization.

26721681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1272471.

The product of its digits is 8064, while the sum is 33.

The square root of 26721681 is about 5169.3017903775. The cubic root of 26721681 is about 298.9656265598.

The spelling of 26721681 in words is "twenty-six million, seven hundred twenty-one thousand, six hundred eighty-one".