221221650261 has 8 divisors (see below), whose sum is σ = 299116597824. Its totient is φ = 145403901440.

The previous prime is 221221650257. The next prime is 221221650271. The reversal of 221221650261 is 162056122122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221221650261 - 2² = 221221650257 is a prime.

It is a super-3 number, since 3×221221650261³ (a number of 35 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221650271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 519299436 + ... + 519299861.

It is an arithmetic number, because the mean of its divisors is an integer number (37389574728).

Almost surely, 2^221221650261 is an apocalyptic number.

It is an amenable number.

221221650261 is a deficient number, since it is larger than the sum of its proper divisors (77894947563).

221221650261 is a wasteful number, since it uses less digits than its factorization.

221221650261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1038599371.

The product of its (nonzero) digits is 5760, while the sum is 30.

Adding to 221221650261 its reverse (162056122122), we get a palindrome (383277772383).

The spelling of 221221650261 in words is "two hundred twenty-one billion, two hundred twenty-one million, six hundred fifty thousand, two hundred sixty-one".