147312721 has 4 divisors (see below), whose sum is σ = 152392500. Its totient is φ = 142232944.

The previous prime is 147312709. The next prime is 147312727. The reversal of 147312721 is 127213741.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127213741 = 127 ⋅1001683.

It can be written as a sum of positive squares in 2 ways, for example, as 40500496 + 106812225 = 6364^2 + 10335^2 .

It is a cyclic number.

It is not a de Polignac number, because 147312721 - 2⁵ = 147312689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 147312721.

It is not an unprimeable number, because it can be changed into a prime (147312727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2539846 + ... + 2539903.

It is an arithmetic number, because the mean of its divisors is an integer number (38098125).

Almost surely, 2^147312721 is an apocalyptic number.

It is an amenable number.

147312721 is a deficient number, since it is larger than the sum of its proper divisors (5079779).

147312721 is an equidigital number, since it uses as much as digits as its factorization.

147312721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5079778.

The product of its digits is 2352, while the sum is 28.

The square root of 147312721 is about 12137.2451981494. The cubic root of 147312721 is about 528.1371900644.

The spelling of 147312721 in words is "one hundred forty-seven million, three hundred twelve thousand, seven hundred twenty-one".