91990890000 has 375 divisors, whose sum is σ = 333694087617. Its totient is φ = 24458112000.

The previous prime is 91990889959. The next prime is 91990890001. The reversal of 91990890000 is 9809919.

The square root of 91990890000 is 303300.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 7 ways, for example, as 85809156624 + 6181733376 = 292932^2 + 78624^2 .

It is a tau number, because it is divible by the number of its divisors (375).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (91990890001) by changing a digit.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 272969832 + ... + 272970168.

Almost surely, 2^91990890000 is an apocalyptic number.

91990890000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

91990890000 is the 303300-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91990890000

91990890000 is an abundant number, since it is smaller than the sum of its proper divisors (241703197617).

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

91990890000 is an frugal number, since it uses more digits than its factorization.

91990890000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714 (or 347 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 45.

The spelling of 91990890000 in words is "ninety-one billion, nine hundred ninety million, eight hundred ninety thousand".