75015721 has 8 divisors (see below), whose sum is σ = 84657600. Its totient is φ = 65844240.

The previous prime is 75015701. The next prime is 75015739. The reversal of 75015721 is 12751057.

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

It is not a de Polignac number, because 75015721 - 2¹³ = 75007529 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 75015721.

It is not an unprimeable number, because it can be changed into a prime (75015701) 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, 117261 + ... + 117898.

It is an arithmetic number, because the mean of its divisors is an integer number (10582200).

Almost surely, 2^75015721 is an apocalyptic number.

It is an amenable number.

75015721 is a deficient number, since it is larger than the sum of its proper divisors (9641879).

75015721 is a wasteful number, since it uses less digits than its factorization.

75015721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235199.

The product of its (nonzero) digits is 2450, while the sum is 28.

The square root of 75015721 is about 8661.1616426436. The cubic root of 75015721 is about 421.7457963810.

Adding to 75015721 its reverse (12751057), we get a palindrome (87766778).

It can be divided in two parts, 750 and 15721, that added together give a triangular number (16471 = T₁₈₁).

The spelling of 75015721 in words is "seventy-five million, fifteen thousand, seven hundred twenty-one".