66098557491 has 4 divisors (see below), whose sum is σ = 88131409992. Its totient is φ = 44065704992.

The previous prime is 66098557457. The next prime is 66098557573. The reversal of 66098557491 is 19475589066.

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 66098557491 - 2³¹ = 63951073843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66098557451) 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, 11016426246 + ... + 11016426251.

It is an arithmetic number, because the mean of its divisors is an integer number (22032852498).

Almost surely, 2^66098557491 is an apocalyptic number.

66098557491 is a deficient number, since it is larger than the sum of its proper divisors (22032852501).

66098557491 is a wasteful number, since it uses less digits than its factorization.

66098557491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22032852500.

The product of its (nonzero) digits is 16329600, while the sum is 60.

The spelling of 66098557491 in words is "sixty-six billion, ninety-eight million, five hundred fifty-seven thousand, four hundred ninety-one".