20518123605601 has 16 divisors (see below), whose sum is σ = 21101110829568. Its totient is φ = 19939102041600.

The previous prime is 20518123605533. The next prime is 20518123605649. The reversal of 20518123605601 is 10650632181502.

It is a cyclic number.

It is not a de Polignac number, because 20518123605601 - 2²¹ = 20518121508449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20518123605671) 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, 47261220 + ... + 47693386.

It is an arithmetic number, because the mean of its divisors is an integer number (1318819426848).

Almost surely, 2^{20518123605601} is an apocalyptic number.

It is an amenable number.

20518123605601 is a deficient number, since it is larger than the sum of its proper divisors (582987223967).

20518123605601 is a wasteful number, since it uses less digits than its factorization.

20518123605601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436752.

The product of its (nonzero) digits is 86400, while the sum is 40.

The spelling of 20518123605601 in words is "twenty trillion, five hundred eighteen billion, one hundred twenty-three million, six hundred five thousand, six hundred one".