21523525350445 has 4 divisors (see below), whose sum is σ = 25828230420540. Its totient is φ = 17218820280352.

The previous prime is 21523525350443. The next prime is 21523525350451. The reversal of 21523525350445 is 54405352532512.

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 12233184774409 + 9290340576036 = 3497597^2 + 3048006^2 .

It is a cyclic number.

It is not a de Polignac number, because 21523525350445 - 2¹ = 21523525350443 is a prime.

It is a super-2 number, since 2×21523525350445² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21523525350395 and 21523525350404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21523525350443) 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, 2152352535040 + ... + 2152352535049.

It is an arithmetic number, because the mean of its divisors is an integer number (6457057605135).

Almost surely, 2^{21523525350445} is an apocalyptic number.

It is an amenable number.

21523525350445 is a deficient number, since it is larger than the sum of its proper divisors (4304705070095).

21523525350445 is an equidigital number, since it uses as much as digits as its factorization.

21523525350445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4304705070094.

The product of its (nonzero) digits is 3600000, while the sum is 46.

Adding to 21523525350445 its reverse (54405352532512), we get a palindrome (75928877882957).

The spelling of 21523525350445 in words is "twenty-one trillion, five hundred twenty-three billion, five hundred twenty-five million, three hundred fifty thousand, four hundred forty-five".