91078583787 has 32 divisors (see below), whose sum is σ = 142986240000. Its totient is φ = 57137205600.

The previous prime is 91078583777. The next prime is 91078583803. The reversal of 91078583787 is 78738587019.

It is not a de Polignac number, because 91078583787 - 2²⁴ = 91061806571 is a prime.

It is a super-2 number, since 2×91078583787² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91078583737) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 519339 + ... + 672212.

It is an arithmetic number, because the mean of its divisors is an integer number (4468320000).

Almost surely, 2^91078583787 is an apocalyptic number.

91078583787 is a deficient number, since it is larger than the sum of its proper divisors (51907656213).

91078583787 is a wasteful number, since it uses less digits than its factorization.

91078583787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1191728 (or 1191722 counting only the distinct ones).

The product of its (nonzero) digits is 23708160, while the sum is 63.

The spelling of 91078583787 in words is "ninety-one billion, seventy-eight million, five hundred eighty-three thousand, seven hundred eighty-seven".