91639063491 has 8 divisors (see below), whose sum is σ = 122201056080. Its totient is φ = 61084889952.

The previous prime is 91639063489. The next prime is 91639063493. The reversal of 91639063491 is 19436093619.

It is an interprime number because it is at equal distance from previous prime (91639063489) and next prime (91639063493).

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

It is not a de Polignac number, because 91639063491 - 2¹ = 91639063489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91639063493) 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, 1927360 + ... + 1974333.

It is an arithmetic number, because the mean of its divisors is an integer number (15275132010).

Almost surely, 2^91639063491 is an apocalyptic number.

91639063491 is a deficient number, since it is larger than the sum of its proper divisors (30561992589).

91639063491 is a wasteful number, since it uses less digits than its factorization.

91639063491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3909525.

The product of its (nonzero) digits is 944784, while the sum is 51.

The spelling of 91639063491 in words is "ninety-one billion, six hundred thirty-nine million, sixty-three thousand, four hundred ninety-one".