1525122661 has 4 divisors (see below), whose sum is σ = 1525293324. Its totient is φ = 1524952000.

The previous prime is 1525122637. The next prime is 1525122691. The reversal of 1525122661 is 1662215251.

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 1383393636 + 141729025 = 37194^2 + 11905^2 .

It is a cyclic number.

It is not a de Polignac number, because 1525122661 - 2⁹ = 1525122149 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1525122611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71140 + ... + 90061.

It is an arithmetic number, because the mean of its divisors is an integer number (381323331).

Almost surely, 2^1525122661 is an apocalyptic number.

It is an amenable number.

1525122661 is a deficient number, since it is larger than the sum of its proper divisors (170663).

1525122661 is an equidigital number, since it uses as much as digits as its factorization.

1525122661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170662.

The product of its digits is 7200, while the sum is 31.

The square root of 1525122661 is about 39052.8188611270. The cubic root of 1525122661 is about 1151.0696188242.

The spelling of 1525122661 in words is "one billion, five hundred twenty-five million, one hundred twenty-two thousand, six hundred sixty-one".