99684079781 has 8 divisors (see below), whose sum is σ = 117111366624. Its totient is φ = 83650975920.

The previous prime is 99684079777. The next prime is 99684079793. The reversal of 99684079781 is 18797048699.

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 99684079781 - 2² = 99684079777 is a prime.

It is a super-2 number, since 2×99684079781² (a number of 23 digits) contains 22 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 (99684079721) 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, 348545591 + ... + 348545876.

It is an arithmetic number, because the mean of its divisors is an integer number (14638920828).

Almost surely, 2^99684079781 is an apocalyptic number.

It is an amenable number.

99684079781 is a deficient number, since it is larger than the sum of its proper divisors (17427286843).

99684079781 is a wasteful number, since it uses less digits than its factorization.

99684079781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 697091491.

The product of its (nonzero) digits is 54867456, while the sum is 68.

The spelling of 99684079781 in words is "ninety-nine billion, six hundred eighty-four million, seventy-nine thousand, seven hundred eighty-one".