26520991 has 4 divisors (see below), whose sum is σ = 30309712. Its totient is φ = 22732272.

The previous prime is 26520983. The next prime is 26520997. The reversal of 26520991 is 19902562.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19902562 = 2 ⋅9951281.

It is a cyclic number.

It is not a de Polignac number, because 26520991 - 2³ = 26520983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26520997) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1894350 + ... + 1894363.

It is an arithmetic number, because the mean of its divisors is an integer number (7577428).

Almost surely, 2^26520991 is an apocalyptic number.

26520991 is a deficient number, since it is larger than the sum of its proper divisors (3788721).

26520991 is an equidigital number, since it uses as much as digits as its factorization.

26520991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3788720.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 26520991 is about 5149.8534930617. The cubic root of 26520991 is about 298.2152964237.

The spelling of 26520991 in words is "twenty-six million, five hundred twenty thousand, nine hundred ninety-one".