26421721 has 4 divisors (see below), whose sum is σ = 26485200. Its totient is φ = 26358244.

The previous prime is 26421713. The next prime is 26421739. The reversal of 26421721 is 12712462.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 26421721 - 2³ = 26421713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26421751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31111 + ... + 31948.

It is an arithmetic number, because the mean of its divisors is an integer number (6621300).

Almost surely, 2^26421721 is an apocalyptic number.

It is an amenable number.

26421721 is a deficient number, since it is larger than the sum of its proper divisors (63479).

26421721 is an equidigital number, since it uses as much as digits as its factorization.

26421721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63478.

The product of its digits is 1344, while the sum is 25.

The square root of 26421721 is about 5140.2063188164. The cubic root of 26421721 is about 297.8427506931.

The spelling of 26421721 in words is "twenty-six million, four hundred twenty-one thousand, seven hundred twenty-one".