105231721 has 8 divisors (see below), whose sum is σ = 120470400. Its totient is φ = 90044448.

The previous prime is 105231703. The next prime is 105231733. The reversal of 105231721 is 127132501.

It is a happy number.

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 105231721 - 2⁷ = 105231593 is a prime.

It is a super-2 number, since 2×105231721² = 22147430209243682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 105231692 and 105231701.

It is not an unprimeable number, because it can be changed into a prime (105231781) 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, 8356 + ... + 16741.

It is an arithmetic number, because the mean of its divisors is an integer number (15058800).

Almost surely, 2^105231721 is an apocalyptic number.

It is an amenable number.

105231721 is a deficient number, since it is larger than the sum of its proper divisors (15238679).

105231721 is an equidigital number, since it uses as much as digits as its factorization.

105231721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25703.

The product of its (nonzero) digits is 420, while the sum is 22.

The square root of 105231721 is about 10258.2513617088. The cubic root of 105231721 is about 472.1161871038.

The spelling of 105231721 in words is "one hundred five million, two hundred thirty-one thousand, seven hundred twenty-one".