221522420525 has 18 divisors (see below), whose sum is σ = 319534791210. Its totient is φ = 151901087520.

The previous prime is 221522420521. The next prime is 221522420531. The reversal of 221522420525 is 525024225122.

It can be written as a sum of positive squares in 3 ways, for example, as 62751252004 + 158771168521 = 250502^2 + 398461^2 .

It is not a de Polignac number, because 221522420525 - 2² = 221522420521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221522420491 and 221522420500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221522420521) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 90416090 + ... + 90418539.

It is an arithmetic number, because the mean of its divisors is an integer number (17751932845).

Almost surely, 2^221522420525 is an apocalyptic number.

221522420525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

221522420525 is a deficient number, since it is larger than the sum of its proper divisors (98012370685).

221522420525 is a wasteful number, since it uses less digits than its factorization.

221522420525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180834653 (or 180834641 counting only the distinct ones).

The product of its (nonzero) digits is 32000, while the sum is 32.

Adding to 221522420525 its reverse (525024225122), we get a palindrome (746546645647).

The spelling of 221522420525 in words is "two hundred twenty-one billion, five hundred twenty-two million, four hundred twenty thousand, five hundred twenty-five".