20154312065 has 4 divisors (see below), whose sum is σ = 24185174484. Its totient is φ = 16123449648.

The previous prime is 20154312053. The next prime is 20154312103. The reversal of 20154312065 is 56021345102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56021345102 = 2 ⋅28010672551.

It can be written as a sum of positive squares in 2 ways, for example, as 2350213441 + 17804098624 = 48479^2 + 133432^2 .

It is a cyclic number.

It is not a de Polignac number, because 20154312065 - 2⁴ = 20154312049 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2015431202 + ... + 2015431211.

It is an arithmetic number, because the mean of its divisors is an integer number (6046293621).

Almost surely, 2^20154312065 is an apocalyptic number.

It is an amenable number.

20154312065 is a deficient number, since it is larger than the sum of its proper divisors (4030862419).

20154312065 is an equidigital number, since it uses as much as digits as its factorization.

20154312065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4030862418.

The product of its (nonzero) digits is 7200, while the sum is 29.

Adding to 20154312065 its reverse (56021345102), we get a palindrome (76175657167).

The spelling of 20154312065 in words is "twenty billion, one hundred fifty-four million, three hundred twelve thousand, sixty-five".