75717721 has 4 divisors (see below), whose sum is σ = 75769344. Its totient is φ = 75666100.

The previous prime is 75717713. The next prime is 75717727. The reversal of 75717721 is 12771757.

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 a cyclic number.

It is not a de Polignac number, because 75717721 - 2³ = 75717713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (75717727) 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, 23545 + ... + 26566.

It is an arithmetic number, because the mean of its divisors is an integer number (18942336).

Almost surely, 2^75717721 is an apocalyptic number.

It is an amenable number.

75717721 is a deficient number, since it is larger than the sum of its proper divisors (51623).

75717721 is a wasteful number, since it uses less digits than its factorization.

75717721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51622.

The product of its digits is 24010, while the sum is 37.

The square root of 75717721 is about 8701.5930150749. The cubic root of 75717721 is about 423.0572849855.

The spelling of 75717721 in words is "seventy-five million, seven hundred seventeen thousand, seven hundred twenty-one".