133724721 has 8 divisors (see below), whose sum is σ = 192015040. Its totient is φ = 82292112.

The previous prime is 133724699. The next prime is 133724743. The reversal of 133724721 is 127427331.

It is an interprime number because it is at equal distance from previous prime (133724699) and next prime (133724743).

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

It is not a de Polignac number, because 133724721 - 2⁹ = 133724209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (133724221) 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, 1714381 + ... + 1714458.

It is an arithmetic number, because the mean of its divisors is an integer number (24001880).

Almost surely, 2^133724721 is an apocalyptic number.

It is an amenable number.

133724721 is a deficient number, since it is larger than the sum of its proper divisors (58290319).

133724721 is a wasteful number, since it uses less digits than its factorization.

133724721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3428855.

The product of its digits is 7056, while the sum is 30.

The square root of 133724721 is about 11563.9405481004. The cubic root of 133724721 is about 511.3723400488.

The spelling of 133724721 in words is "one hundred thirty-three million, seven hundred twenty-four thousand, seven hundred twenty-one".