20851181345 has 16 divisors (see below), whose sum is σ = 25470793872. Its totient is φ = 16382204160.

The previous prime is 20851181311. The next prime is 20851181363. The reversal of 20851181345 is 54318115802.

It can be written as a sum of positive squares in 8 ways, for example, as 2833219984 + 18017961361 = 53228^2 + 134231^2 .

It is not a de Polignac number, because 20851181345 - 2⁸ = 20851181089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20851181299 and 20851181308.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 146819 + ... + 251511.

It is an arithmetic number, because the mean of its divisors is an integer number (1591924617).

Almost surely, 2^20851181345 is an apocalyptic number.

It is an amenable number.

20851181345 is a deficient number, since it is larger than the sum of its proper divisors (4619612527).

20851181345 is a wasteful number, since it uses less digits than its factorization.

20851181345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105412.

The product of its (nonzero) digits is 38400, while the sum is 38.

The spelling of 20851181345 in words is "twenty billion, eight hundred fifty-one million, one hundred eighty-one thousand, three hundred forty-five".