20145411521 has 4 divisors (see below), whose sum is σ = 20146714500. Its totient is φ = 20144108544.

The previous prime is 20145411509. The next prime is 20145411563. The reversal of 20145411521 is 12511454102.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6652033600 + 13493377921 = 81560^2 + 116161^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20145411521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20145411421) 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, 628016 + ... + 659313.

It is an arithmetic number, because the mean of its divisors is an integer number (5036678625).

Almost surely, 2^20145411521 is an apocalyptic number.

It is an amenable number.

20145411521 is a deficient number, since it is larger than the sum of its proper divisors (1302979).

20145411521 is a wasteful number, since it uses less digits than its factorization.

20145411521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1302978.

The product of its (nonzero) digits is 1600, while the sum is 26.

Adding to 20145411521 its reverse (12511454102), we get a palindrome (32656865623).

The spelling of 20145411521 in words is "twenty billion, one hundred forty-five million, four hundred eleven thousand, five hundred twenty-one".