75011721 has 8 divisors (see below), whose sum is σ = 100110720. Its totient is φ = 49960272.

The previous prime is 75011711. The next prime is 75011771. The reversal of 75011721 is 12711057.

It is a happy number.

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

It is not a de Polignac number, because 75011721 - 2⁷ = 75011593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 75011691 and 75011700.

It is not an unprimeable number, because it can be changed into a prime (75011711) 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, 8026 + ... + 14643.

It is an arithmetic number, because the mean of its divisors is an integer number (12513840).

Almost surely, 2^75011721 is an apocalyptic number.

It is an amenable number.

75011721 is a deficient number, since it is larger than the sum of its proper divisors (25098999).

75011721 is a wasteful number, since it uses less digits than its factorization.

75011721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23775.

The product of its (nonzero) digits is 490, while the sum is 24.

The square root of 75011721 is about 8660.9307236578. The cubic root of 75011721 is about 421.7383001160.

Adding to 75011721 its reverse (12711057), we get a palindrome (87722778).

The spelling of 75011721 in words is "seventy-five million, eleven thousand, seven hundred twenty-one".