7556135721 has 16 divisors (see below), whose sum is σ = 10144100544. Its totient is φ = 5002830144.

The previous prime is 7556135701. The next prime is 7556135731. The reversal of 7556135721 is 1275316557.

It is not a de Polignac number, because 7556135721 - 2¹³ = 7556127529 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (7556135701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1729686 + ... + 1734048.

It is an arithmetic number, because the mean of its divisors is an integer number (634006284).

Almost surely, 2^7556135721 is an apocalyptic number.

It is an amenable number.

7556135721 is a deficient number, since it is larger than the sum of its proper divisors (2587964823).

7556135721 is a wasteful number, since it uses less digits than its factorization.

7556135721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8200.

The product of its digits is 220500, while the sum is 42.

The square root of 7556135721 is about 86926.0359213510. The cubic root of 7556135721 is about 1962.3053293102.

The spelling of 7556135721 in words is "seven billion, five hundred fifty-six million, one hundred thirty-five thousand, seven hundred twenty-one".