91007687621 has 8 divisors (see below), whose sum is σ = 93474290424. Its totient is φ = 88541449920.

The previous prime is 91007687599. The next prime is 91007687627. The reversal of 91007687621 is 12678670019.

It can be written as a sum of positive squares in 4 ways, for example, as 68165899396 + 22841788225 = 261086^2 + 151135^2 .

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

It is not a de Polignac number, because 91007687621 - 2⁶ = 91007687557 is a prime.

It is a super-2 number, since 2×91007687621² (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 (91007687627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 458231 + ... + 626091.

It is an arithmetic number, because the mean of its divisors is an integer number (11684286303).

Almost surely, 2^91007687621 is an apocalyptic number.

It is an amenable number.

91007687621 is a deficient number, since it is larger than the sum of its proper divisors (2466602803).

91007687621 is a wasteful number, since it uses less digits than its factorization.

91007687621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182551.

The product of its (nonzero) digits is 254016, while the sum is 47.

The spelling of 91007687621 in words is "ninety-one billion, seven million, six hundred eighty-seven thousand, six hundred twenty-one".