21221523045513 has 20 divisors (see below), whose sum is σ = 36230042872320. Its totient is φ = 12126584597112.

The previous prime is 21221523045491. The next prime is 21221523045521. The reversal of 21221523045513 is 31554032512212.

21221523045513 is a `hidden beast` number, since 2 + 1 + 2 + 21 + 52 + 30 + 4 + 551 + 3 = 666.

It is not a de Polignac number, because 21221523045513 - 2⁶ = 21221523045449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221523047513) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18713864553 + ... + 18713865686.

It is an arithmetic number, because the mean of its divisors is an integer number (1811502143616).

Almost surely, 2^{21221523045513} is an apocalyptic number.

It is an amenable number.

21221523045513 is a deficient number, since it is larger than the sum of its proper divisors (15008519826807).

21221523045513 is an equidigital number, since it uses as much as digits as its factorization.

21221523045513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37427730258 (or 37427730249 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

Adding to 21221523045513 its reverse (31554032512212), we get a palindrome (52775555557725).

The spelling of 21221523045513 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred twenty-three million, forty-five thousand, five hundred thirteen".