90806531821 has 8 divisors (see below), whose sum is σ = 91532648480. Its totient is φ = 90082285488.

The previous prime is 90806531779. The next prime is 90806531833. The reversal of 90806531821 is 12813560809.

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 90806531821 - 2¹⁷ = 90806400749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90806531521) 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, 370011 + ... + 564376.

It is an arithmetic number, because the mean of its divisors is an integer number (11441581060).

Almost surely, 2^90806531821 is an apocalyptic number.

It is an amenable number.

90806531821 is a deficient number, since it is larger than the sum of its proper divisors (726116659).

90806531821 is a wasteful number, since it uses less digits than its factorization.

90806531821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 935163.

The product of its (nonzero) digits is 103680, while the sum is 43.

The spelling of 90806531821 in words is "ninety billion, eight hundred six million, five hundred thirty-one thousand, eight hundred twenty-one".