91083251621 has 8 divisors (see below), whose sum is σ = 91361789400. Its totient is φ = 90804814848.

The previous prime is 91083251573. The next prime is 91083251657. The reversal of 91083251621 is 12615238019.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 67883697025 + 23199554596 = 260545^2 + 152314^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 91083251621 - 2⁶ = 91083251557 is a prime.

It is a super-3 number, since 3×91083251621³ (a number of 34 digits) contains 333 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 (91083211621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2035925 + ... + 2080181.

It is an arithmetic number, because the mean of its divisors is an integer number (11420223675).

Almost surely, 2^91083251621 is an apocalyptic number.

It is an amenable number.

91083251621 is a deficient number, since it is larger than the sum of its proper divisors (278537779).

91083251621 is a wasteful number, since it uses less digits than its factorization.

91083251621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50503.

The product of its (nonzero) digits is 25920, while the sum is 38.

The spelling of 91083251621 in words is "ninety-one billion, eighty-three million, two hundred fifty-one thousand, six hundred twenty-one".