20123506536661 has 16 divisors (see below), whose sum is σ = 21986692574400. Its totient is φ = 18265956508800.

The previous prime is 20123506536649. The next prime is 20123506536673. The reversal of 20123506536661 is 16663560532102.

It is an interprime number because it is at equal distance from previous prime (20123506536649) and next prime (20123506536673).

It is not a de Polignac number, because 20123506536661 - 2⁵ = 20123506536629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123506536611) 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, 62301106 + ... + 62623276.

It is an arithmetic number, because the mean of its divisors is an integer number (1374168285900).

Almost surely, 2^{20123506536661} is an apocalyptic number.

It is an amenable number.

20123506536661 is a deficient number, since it is larger than the sum of its proper divisors (1863186037739).

20123506536661 is a wasteful number, since it uses less digits than its factorization.

20123506536661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330900.

The product of its (nonzero) digits is 1166400, while the sum is 46.

The spelling of 20123506536661 in words is "twenty trillion, one hundred twenty-three billion, five hundred six million, five hundred thirty-six thousand, six hundred sixty-one".