91009556650 has 48 divisors (see below), whose sum is σ = 174794669568. Its totient is φ = 35218152000.

The previous prime is 91009556623. The next prime is 91009556653. The reversal of 91009556650 is 5665590019.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 91009556650.

It is not an unprimeable number, because it can be changed into a prime (91009556653) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6054544 + ... + 6069556.

It is an arithmetic number, because the mean of its divisors is an integer number (3641555616).

Almost surely, 2^91009556650 is an apocalyptic number.

91009556650 is a deficient number, since it is larger than the sum of its proper divisors (83785112918).

91009556650 is a wasteful number, since it uses less digits than its factorization.

91009556650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18967 (or 18962 counting only the distinct ones).

The product of its (nonzero) digits is 364500, while the sum is 46.

It can be divided in two parts, 910095 and 56650, that added together give a triangular number (966745 = T₁₃₉₀).

The spelling of 91009556650 in words is "ninety-one billion, nine million, five hundred fifty-six thousand, six hundred fifty".