20115407521 has 16 divisors (see below), whose sum is σ = 23443810560. Its totient is φ = 17065691280.

The previous prime is 20115407467. The next prime is 20115407527. The reversal of 20115407521 is 12570451102.

It is not a de Polignac number, because 20115407521 - 2¹³ = 20115399329 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20115407521.

It is not an unprimeable number, because it can be changed into a prime (20115407527) 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 15 ways as a sum of consecutive naturals, for example, 704251 + ... + 732256.

It is an arithmetic number, because the mean of its divisors is an integer number (1465238160).

Almost surely, 2^20115407521 is an apocalyptic number.

It is an amenable number.

20115407521 is a deficient number, since it is larger than the sum of its proper divisors (3328403039).

20115407521 is a wasteful number, since it uses less digits than its factorization.

20115407521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1436604.

The product of its (nonzero) digits is 2800, while the sum is 28.

Adding to 20115407521 its reverse (12570451102), we get a palindrome (32685858623).

The spelling of 20115407521 in words is "twenty billion, one hundred fifteen million, four hundred seven thousand, five hundred twenty-one".