20154566513 has 4 divisors (see below), whose sum is σ = 20646141348. Its totient is φ = 19662991680.

The previous prime is 20154566501. The next prime is 20154566533. The reversal of 20154566513 is 31566545102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31566545102 = 2 ⋅15783272551.

It can be written as a sum of positive squares in 2 ways, for example, as 7915127089 + 12239439424 = 88967^2 + 110632^2 .

It is a cyclic number.

It is not a de Polignac number, because 20154566513 - 2⁶ = 20154566449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20154566533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 245787356 + ... + 245787437.

It is an arithmetic number, because the mean of its divisors is an integer number (5161535337).

Almost surely, 2^20154566513 is an apocalyptic number.

It is an amenable number.

20154566513 is a deficient number, since it is larger than the sum of its proper divisors (491574835).

20154566513 is an equidigital number, since it uses as much as digits as its factorization.

20154566513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491574834.

The product of its (nonzero) digits is 108000, while the sum is 38.

The spelling of 20154566513 in words is "twenty billion, one hundred fifty-four million, five hundred sixty-six thousand, five hundred thirteen".