65641455891 has 96 divisors (see below), whose sum is σ = 112460544000. Its totient is φ = 37756635840.

The previous prime is 65641455883. The next prime is 65641455899. The reversal of 65641455891 is 19855414656.

It is a happy number.

65641455891 is a `hidden beast` number, since 6 + 56 + 4 + 1 + 4 + 5 + 589 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (65641455883) and next prime (65641455899).

It is not a de Polignac number, because 65641455891 - 2³ = 65641455883 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (65641455899) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5583966 + ... + 5595708.

It is an arithmetic number, because the mean of its divisors is an integer number (1171464000).

Almost surely, 2^65641455891 is an apocalyptic number.

65641455891 is a deficient number, since it is larger than the sum of its proper divisors (46819088109).

65641455891 is a wasteful number, since it uses less digits than its factorization.

65641455891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11862 (or 11845 counting only the distinct ones).

The product of its digits is 5184000, while the sum is 54.

The spelling of 65641455891 in words is "sixty-five billion, six hundred forty-one million, four hundred fifty-five thousand, eight hundred ninety-one".