7924809905 has 8 divisors (see below), whose sum is σ = 9510791784. Its totient is φ = 6339168000.

The previous prime is 7924809881. The next prime is 7924809917. The reversal of 7924809905 is 5099084297.

It can be written as a sum of positive squares in 4 ways, for example, as 5495108641 + 2429701264 = 74129^2 + 49292^2 .

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

It is not a de Polignac number, because 7924809905 - 2¹⁴ = 7924793521 is a prime.

It is a super-2 number, since 2×7924809905² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30536 + ... + 129545.

It is an arithmetic number, because the mean of its divisors is an integer number (1188848973).

Almost surely, 2^7924809905 is an apocalyptic number.

It is an amenable number.

7924809905 is a deficient number, since it is larger than the sum of its proper divisors (1585981879).

7924809905 is a wasteful number, since it uses less digits than its factorization.

7924809905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169987.

The product of its (nonzero) digits is 1632960, while the sum is 53.

The square root of 7924809905 is about 89021.4013875315. The cubic root of 7924809905 is about 1993.7144252193.

The spelling of 7924809905 in words is "seven billion, nine hundred twenty-four million, eight hundred nine thousand, nine hundred five".