1661525345 has 16 divisors (see below), whose sum is σ = 2113315920. Its totient is φ = 1249726464.

The previous prime is 1661525323. The next prime is 1661525347. The reversal of 1661525345 is 5435251661.

It can be written as a sum of positive squares in 8 ways, for example, as 28718881 + 1632806464 = 5359^2 + 40408^2 .

It is a cyclic number.

It is not a de Polignac number, because 1661525345 - 2¹² = 1661521249 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1661525299 and 1661525308.

It is not an unprimeable number, because it can be changed into a prime (1661525347) 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, 76079 + ... + 95451.

It is an arithmetic number, because the mean of its divisors is an integer number (132082245).

Almost surely, 2^1661525345 is an apocalyptic number.

It is an amenable number.

1661525345 is a deficient number, since it is larger than the sum of its proper divisors (451790575).

1661525345 is a wasteful number, since it uses less digits than its factorization.

1661525345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20404.

The product of its digits is 108000, while the sum is 38.

The square root of 1661525345 is about 40761.8123370392. The cubic root of 1661525345 is about 1184.4107035693.

The spelling of 1661525345 in words is "one billion, six hundred sixty-one million, five hundred twenty-five thousand, three hundred forty-five".