7563781521 has 12 divisors (see below), whose sum is σ = 10933994448. Its totient is φ = 5038583064.

The previous prime is 7563781507. The next prime is 7563781531. The reversal of 7563781521 is 1251873657.

It is a happy number.

7563781521 is a `hidden beast` number, since 7 + 5 + 637 + 8 + 1 + 5 + 2 + 1 = 666.

7563781521 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 7563781521 - 2⁹ = 7563781009 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7563781531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 315975 + ... + 339068.

It is an arithmetic number, because the mean of its divisors is an integer number (911166204).

Almost surely, 2^7563781521 is an apocalyptic number.

It is an amenable number.

7563781521 is a deficient number, since it is larger than the sum of its proper divisors (3370212927).

7563781521 is a wasteful number, since it uses less digits than its factorization.

7563781521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656332 (or 656329 counting only the distinct ones).

The product of its digits is 352800, while the sum is 45.

The square root of 7563781521 is about 86970.0035701965. The cubic root of 7563781521 is about 1962.9669698192.

The spelling of 7563781521 in words is "seven billion, five hundred sixty-three million, seven hundred eighty-one thousand, five hundred twenty-one".