20665820515 has 8 divisors (see below), whose sum is σ = 24810580368. Its totient is φ = 16524925920.

The previous prime is 20665820503. The next prime is 20665820533. The reversal of 20665820515 is 51502856602.

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

It is not a de Polignac number, because 20665820515 - 2⁷ = 20665820387 is a prime.

It is a super-2 number, since 2×20665820515² (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, 954537 + ... + 975946.

It is an arithmetic number, because the mean of its divisors is an integer number (3101322546).

Almost surely, 2^20665820515 is an apocalyptic number.

20665820515 is a deficient number, since it is larger than the sum of its proper divisors (4144759853).

20665820515 is a wasteful number, since it uses less digits than its factorization.

20665820515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1932629.

The product of its (nonzero) digits is 144000, while the sum is 40.

The spelling of 20665820515 in words is "twenty billion, six hundred sixty-five million, eight hundred twenty thousand, five hundred fifteen".