229901721 has 32 divisors (see below), whose sum is σ = 366778368. Its totient is φ = 125241600.

The previous prime is 229901717. The next prime is 229901743. The reversal of 229901721 is 127109922.

It is not a de Polignac number, because 229901721 - 2² = 229901717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (229801721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 193090 + ... + 194276.

It is an arithmetic number, because the mean of its divisors is an integer number (11461824).

Almost surely, 2^229901721 is an apocalyptic number.

229901721 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

229901721 is a deficient number, since it is larger than the sum of its proper divisors (136876647).

229901721 is a wasteful number, since it uses less digits than its factorization.

229901721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1621.

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 229901721 is about 15162.5103792215. The cubic root of 229901721 is about 612.6052872453.

The spelling of 229901721 in words is "two hundred twenty-nine million, nine hundred one thousand, seven hundred twenty-one".