99657238681 has 32 divisors (see below), whose sum is σ = 134405849088. Its totient is φ = 71359928640.

The previous prime is 99657238673. The next prime is 99657238693. The reversal of 99657238681 is 18683275699.

99657238681 is a nontrivial binomial coefficient, being equal to C(446447, 2).

It is not a de Polignac number, because 99657238681 - 2³ = 99657238673 is a prime.

It is a super-2 number, since 2×99657238681² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (99657238651) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1 + ... + 446446.

It is an arithmetic number, because the mean of its divisors is an integer number (4200182784).

Almost surely, 2^99657238681 is an apocalyptic number.

99657238681 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

99657238681 is the 446446-th triangular number.

99657238681 is the 148816-th centered nonagonal number.

It is an amenable number.

99657238681 is a deficient number, since it is larger than the sum of its proper divisors (34748610407).

99657238681 is a wasteful number, since it uses less digits than its factorization.

99657238681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446701.

The product of its digits is 39191040, while the sum is 64.

The spelling of 99657238681 in words is "ninety-nine billion, six hundred fifty-seven million, two hundred thirty-eight thousand, six hundred eighty-one".