99980542809 has 105 divisors (see below), whose sum is σ = 175610299973. Its totient is φ = 56892693816.

The previous prime is 99980542807. The next prime is 99980542811. The reversal of 99980542809 is 90824508999.

The square root of 99980542809 is 316197.

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

99980542809 is a `hidden beast` number, since 9 + 9 + 9 + 8 + 0 + 542 + 80 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (99980542807) and next prime (99980542811).

It is not a de Polignac number, because 99980542809 - 2¹ = 99980542807 is a prime.

It is a super-2 number, since 2×99980542809² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99980542807) by changing a digit.

It is a polite number, since it can be written in 104 ways as a sum of consecutive naturals, for example, 418328512 + ... + 418328750.

Almost surely, 2^99980542809 is an apocalyptic number.

99980542809 is the 316197-th square number.

99980542809 is the 158099-th centered octagonal number.

It is an amenable number.

99980542809 is a deficient number, since it is larger than the sum of its proper divisors (75629757164).

99980542809 is an frugal number, since it uses more digits than its factorization.

99980542809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524 (or 249 counting only the distinct ones).

The product of its (nonzero) digits is 16796160, while the sum is 63.

The spelling of 99980542809 in words is "ninety-nine billion, nine hundred eighty million, five hundred forty-two thousand, eight hundred nine".