20538865949 has 4 divisors (see below), whose sum is σ = 23472989664. Its totient is φ = 17604742236.

The previous prime is 20538865937. The next prime is 20538865951. The reversal of 20538865949 is 94956883502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20538865949 - 2²⁰ = 20537817373 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 (20538865999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1467061847 + ... + 1467061860.

It is an arithmetic number, because the mean of its divisors is an integer number (5868247416).

Almost surely, 2^20538865949 is an apocalyptic number.

It is an amenable number.

20538865949 is a deficient number, since it is larger than the sum of its proper divisors (2934123715).

20538865949 is an equidigital number, since it uses as much as digits as its factorization.

20538865949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2934123714.

The product of its (nonzero) digits is 18662400, while the sum is 59.

The spelling of 20538865949 in words is "twenty billion, five hundred thirty-eight million, eight hundred sixty-five thousand, nine hundred forty-nine".