26907991 has 16 divisors (see below), whose sum is σ = 31929120. Its totient is φ = 22394880.

The previous prime is 26907989. The next prime is 26907997. The reversal of 26907991 is 19970962.

It is a 11-Lehmer number, since φ(26907991) divides (26907991-1)¹¹.

It is a cyclic number.

It is not a de Polignac number, because 26907991 - 2¹ = 26907989 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 (26907997) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4975 + ... + 8863.

It is an arithmetic number, because the mean of its divisors is an integer number (1995570).

Almost surely, 2^26907991 is an apocalyptic number.

26907991 is a deficient number, since it is larger than the sum of its proper divisors (5021129).

26907991 is a wasteful number, since it uses less digits than its factorization.

26907991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3954.

The product of its (nonzero) digits is 61236, while the sum is 43.

The square root of 26907991 is about 5187.2912970066. The cubic root of 26907991 is about 299.6588381015.

The spelling of 26907991 in words is "twenty-six million, nine hundred seven thousand, nine hundred ninety-one".