1661125389 has 96 divisors (see below), whose sum is σ = 2975250432. Its totient is φ = 804988800.

The previous prime is 1661125357. The next prime is 1661125409. The reversal of 1661125389 is 9835211661.

It is not a de Polignac number, because 1661125389 - 2⁵ = 1661125357 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1661125389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661125189) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2512719 + ... + 2513379.

It is an arithmetic number, because the mean of its divisors is an integer number (30992192).

Almost surely, 2^1661125389 is an apocalyptic number.

It is an amenable number.

1661125389 is a deficient number, since it is larger than the sum of its proper divisors (1314125043).

1661125389 is a wasteful number, since it uses less digits than its factorization.

1661125389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 759 (or 748 counting only the distinct ones).

The product of its digits is 77760, while the sum is 42.

The square root of 1661125389 is about 40756.9060283040. The cubic root of 1661125389 is about 1184.3156603441.

The spelling of 1661125389 in words is "one billion, six hundred sixty-one million, one hundred twenty-five thousand, three hundred eighty-nine".