21224550315645 has 32 divisors (see below), whose sum is σ = 37734042551040. Its totient is φ = 11319307571520.

The previous prime is 21224550315601. The next prime is 21224550315713. The reversal of 21224550315645 is 54651305542212.

21224550315645 is a `hidden beast` number, since 2 + 1 + 2 + 2 + 4 + 5 + 50 + 31 + 564 + 5 = 666.

It is not a de Polignac number, because 21224550315645 - 2⁸ = 21224550315389 is a prime.

It is a super-2 number, since 2×21224550315645² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21224550315645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 259507 + ... + 6520463.

It is an arithmetic number, because the mean of its divisors is an integer number (1179188829720).

Almost surely, 2^{21224550315645} is an apocalyptic number.

It is an amenable number.

21224550315645 is a deficient number, since it is larger than the sum of its proper divisors (16509492235395).

21224550315645 is a wasteful number, since it uses less digits than its factorization.

21224550315645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6286082 (or 6286076 counting only the distinct ones).

The product of its (nonzero) digits is 1440000, while the sum is 45.

Adding to 21224550315645 its reverse (54651305542212), we get a palindrome (75875855857857).

The spelling of 21224550315645 in words is "twenty-one trillion, two hundred twenty-four billion, five hundred fifty million, three hundred fifteen thousand, six hundred forty-five".