20521404145 has 8 divisors (see below), whose sum is σ = 26864383680. Its totient is φ = 14924657520.

The previous prime is 20521404143. The next prime is 20521404161. The reversal of 20521404145 is 54140412502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20521404145 - 2¹ = 20521404143 is a prime.

It is a super-2 number, since 2×20521404145² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20521404143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 186558165 + ... + 186558274.

It is an arithmetic number, because the mean of its divisors is an integer number (3358047960).

Almost surely, 2^20521404145 is an apocalyptic number.

It is an amenable number.

20521404145 is a deficient number, since it is larger than the sum of its proper divisors (6342979535).

20521404145 is a wasteful number, since it uses less digits than its factorization.

20521404145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373116455.

The product of its (nonzero) digits is 6400, while the sum is 28.

Adding to 20521404145 its reverse (54140412502), we get a palindrome (74661816647).

The spelling of 20521404145 in words is "twenty billion, five hundred twenty-one million, four hundred four thousand, one hundred forty-five".