91297788047 has 4 divisors (see below), whose sum is σ = 94242878016. Its totient is φ = 88352698080.

The previous prime is 91297787993. The next prime is 91297788053. The reversal of 91297788047 is 74088779219.

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 91297788047 - 2²⁴ = 91281010831 is a prime.

It is a super-2 number, since 2×91297788047² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91297788077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1472544938 + ... + 1472544999.

It is an arithmetic number, because the mean of its divisors is an integer number (23560719504).

Almost surely, 2^91297788047 is an apocalyptic number.

91297788047 is a deficient number, since it is larger than the sum of its proper divisors (2945089969).

91297788047 is a wasteful number, since it uses less digits than its factorization.

91297788047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2945089968.

The product of its (nonzero) digits is 14224896, while the sum is 62.

The spelling of 91297788047 in words is "ninety-one billion, two hundred ninety-seven million, seven hundred eighty-eight thousand, forty-seven".