64969045991 has 4 divisors (see below), whose sum is σ = 65124103800. Its totient is φ = 64813988184.

The previous prime is 64969045961. The next prime is 64969046029. The reversal of 64969045991 is 19954096946.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64969045991 - 2¹⁰ = 64969044967 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 (64969045961) 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, 77528276 + ... + 77529113.

It is an arithmetic number, because the mean of its divisors is an integer number (16281025950).

Almost surely, 2^64969045991 is an apocalyptic number.

64969045991 is a deficient number, since it is larger than the sum of its proper divisors (155057809).

64969045991 is a wasteful number, since it uses less digits than its factorization.

64969045991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155057808.

The product of its (nonzero) digits is 18895680, while the sum is 62.

The spelling of 64969045991 in words is "sixty-four billion, nine hundred sixty-nine million, forty-five thousand, nine hundred ninety-one".