221729361 has 24 divisors (see below), whose sum is σ = 358864704. Its totient is φ = 121191840.

The previous prime is 221729357. The next prime is 221729363. The reversal of 221729361 is 163927122.

221729361 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221729361 - 2² = 221729357 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221729363) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29410 + ... + 36171.

It is an arithmetic number, because the mean of its divisors is an integer number (14952696).

Almost surely, 2^221729361 is an apocalyptic number.

221729361 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221729361 is a deficient number, since it is larger than the sum of its proper divisors (137135343).

221729361 is a wasteful number, since it uses less digits than its factorization.

221729361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65621 (or 65614 counting only the distinct ones).

The product of its digits is 9072, while the sum is 33.

The square root of 221729361 is about 14890.5796059119. The cubic root of 221729361 is about 605.2587386802.

The spelling of 221729361 in words is "two hundred twenty-one million, seven hundred twenty-nine thousand, three hundred sixty-one".