7725061521 has 12 divisors (see below), whose sum is σ = 11160676020. Its totient is φ = 5149000800.

The previous prime is 7725061507. The next prime is 7725061541. The reversal of 7725061521 is 1251605277.

7725061521 is a `hidden beast` number, since 7 + 72 + 5 + 0 + 61 + 521 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3694208400 + 4030853121 = 60780^2 + 63489^2 .

It is not a de Polignac number, because 7725061521 - 2¹⁷ = 7724930449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7725061501) 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, 38226 + ... + 130043.

It is an arithmetic number, because the mean of its divisors is an integer number (930056335).

Almost surely, 2^7725061521 is an apocalyptic number.

It is an amenable number.

7725061521 is a deficient number, since it is larger than the sum of its proper divisors (3435614499).

7725061521 is a wasteful number, since it uses less digits than its factorization.

7725061521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173376 (or 173373 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 36.

The square root of 7725061521 is about 87892.3291362790. The cubic root of 7725061521 is about 1976.8208616487.

Adding to 7725061521 its reverse (1251605277), we get a palindrome (8976666798).

The spelling of 7725061521 in words is "seven billion, seven hundred twenty-five million, sixty-one thousand, five hundred twenty-one".