65108991 has 8 divisors (see below), whose sum is σ = 91381120. Its totient is φ = 41121432.

The previous prime is 65108983. The next prime is 65108993. The reversal of 65108991 is 19980156.

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

It is not a de Polignac number, because 65108991 - 2³ = 65108983 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 (65108993) 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, 571075 + ... + 571188.

It is an arithmetic number, because the mean of its divisors is an integer number (11422640).

Almost surely, 2^65108991 is an apocalyptic number.

65108991 is a deficient number, since it is larger than the sum of its proper divisors (26272129).

65108991 is a wasteful number, since it uses less digits than its factorization.

65108991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1142285.

The product of its (nonzero) digits is 19440, while the sum is 39.

The square root of 65108991 is about 8069.0142520633. The cubic root of 65108991 is about 402.2971800712.

The spelling of 65108991 in words is "sixty-five million, one hundred eight thousand, nine hundred ninety-one".