133772721 has 4 divisors (see below), whose sum is σ = 178363632. Its totient is φ = 89181812.

The previous prime is 133772713. The next prime is 133772729. The reversal of 133772721 is 127277331.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (133772713) and next prime (133772729).

It is a cyclic number.

It is not a de Polignac number, because 133772721 - 2³ = 133772713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (133772729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22295451 + ... + 22295456.

It is an arithmetic number, because the mean of its divisors is an integer number (44590908).

Almost surely, 2^133772721 is an apocalyptic number.

It is an amenable number.

133772721 is a deficient number, since it is larger than the sum of its proper divisors (44590911).

133772721 is an equidigital number, since it uses as much as digits as its factorization.

133772721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44590910.

The product of its digits is 12348, while the sum is 33.

The square root of 133772721 is about 11566.0157789967. The cubic root of 133772721 is about 511.4335178073.

The spelling of 133772721 in words is "one hundred thirty-three million, seven hundred seventy-two thousand, seven hundred twenty-one".