154728721 has 9 divisors (see below), whose sum is σ = 180091899. Its totient is φ = 132549984.

The previous prime is 154728701. The next prime is 154728737. The reversal of 154728721 is 127827451.

The square root of 154728721 is 12439.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 78411025 + 76317696 = 8855^2 + 8736^2 .

It is not a de Polignac number, because 154728721 - 2²³ = 146340113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (154728701) 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 8 ways as a sum of consecutive naturals, for example, 86185 + ... + 87961.

It is an arithmetic number, because the mean of its divisors is an integer number (20010211).

Almost surely, 2^154728721 is an apocalyptic number.

154728721 is the 12439-th square number.

154728721 is the 6220-th centered octagonal number.

It is an amenable number.

154728721 is a deficient number, since it is larger than the sum of its proper divisors (25363178).

154728721 is an frugal number, since it uses more digits than its factorization.

154728721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3568 (or 1784 counting only the distinct ones).

The product of its digits is 31360, while the sum is 37.

The cubic root of 154728721 is about 536.8549706777.

The spelling of 154728721 in words is "one hundred fifty-four million, seven hundred twenty-eight thousand, seven hundred twenty-one".