91061610660 has 72 divisors (see below), whose sum is σ = 285745070520. Its totient is φ = 23445746688.

The previous prime is 91061610617. The next prime is 91061610667. The reversal of 91061610660 is 6601616019.

It can be written as a sum of positive squares in 4 ways, for example, as 23350284864 + 67711325796 = 152808^2 + 260214^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (91061610667) 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, 8717157 + ... + 8727596.

It is an arithmetic number, because the mean of its divisors is an integer number (3968681535).

Almost surely, 2^91061610660 is an apocalyptic number.

91061610660 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

91061610660 is an abundant number, since it is smaller than the sum of its proper divisors (194683459860).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91061610660 is a wasteful number, since it uses less digits than its factorization.

91061610660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17444797 (or 17444792 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The spelling of 91061610660 in words is "ninety-one billion, sixty-one million, six hundred ten thousand, six hundred sixty".