7542663521 has 4 divisors (see below), whose sum is σ = 7542886932. Its totient is φ = 7542440112.

The previous prime is 7542663511. The next prime is 7542663533. The reversal of 7542663521 is 1253662457.

7542663521 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1158653521 + 6384010000 = 34039^2 + 79900^2 .

It is a cyclic number.

It is not a de Polignac number, because 7542663521 - 2²² = 7538469217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7542663511) 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, 49526 + ... + 132431.

It is an arithmetic number, because the mean of its divisors is an integer number (1885721733).

Almost surely, 2^7542663521 is an apocalyptic number.

It is an amenable number.

7542663521 is a deficient number, since it is larger than the sum of its proper divisors (223411).

7542663521 is a wasteful number, since it uses less digits than its factorization.

7542663521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223410.

The product of its digits is 302400, while the sum is 41.

The square root of 7542663521 is about 86848.5090315315. The cubic root of 7542663521 is about 1961.1384058061.

The spelling of 7542663521 in words is "seven billion, five hundred forty-two million, six hundred sixty-three thousand, five hundred twenty-one".