20857715105 has 16 divisors (see below), whose sum is σ = 25462382400. Its totient is φ = 16397620800.

The previous prime is 20857715093. The next prime is 20857715107. The reversal of 20857715105 is 50151775802.

It is not a de Polignac number, because 20857715105 - 2⁶ = 20857715041 is a prime.

It is a super-2 number, since 2×20857715105² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20857715107) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 963086 + ... + 984504.

It is an arithmetic number, because the mean of its divisors is an integer number (1591398900).

Almost surely, 2^20857715105 is an apocalyptic number.

It is an amenable number.

20857715105 is a deficient number, since it is larger than the sum of its proper divisors (4604667295).

20857715105 is a wasteful number, since it uses less digits than its factorization.

20857715105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24784.

The product of its (nonzero) digits is 98000, while the sum is 41.

The spelling of 20857715105 in words is "twenty billion, eight hundred fifty-seven million, seven hundred fifteen thousand, one hundred five".