20511347123 has 16 divisors (see below), whose sum is σ = 21721996800. Its totient is φ = 19327714560.

The previous prime is 20511347117. The next prime is 20511347141. The reversal of 20511347123 is 32174311502.

It is a cyclic number.

It is not a de Polignac number, because 20511347123 - 2⁴ = 20511347107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20511347113) 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, 2378243 + ... + 2386851.

It is an arithmetic number, because the mean of its divisors is an integer number (1357624800).

Almost surely, 2^20511347123 is an apocalyptic number.

20511347123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20511347123 is a deficient number, since it is larger than the sum of its proper divisors (1210649677).

20511347123 is a wasteful number, since it uses less digits than its factorization.

20511347123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10162.

The product of its (nonzero) digits is 5040, while the sum is 29.

Adding to 20511347123 its reverse (32174311502), we get a palindrome (52685658625).

The spelling of 20511347123 in words is "twenty billion, five hundred eleven million, three hundred forty-seven thousand, one hundred twenty-three".