1749128661 has 20 divisors (see below), whose sum is σ = 2986167712. Its totient is φ = 999501768.

The previous prime is 1749128621. The next prime is 1749128663. The reversal of 1749128661 is 1668219471.

It is not a de Polignac number, because 1749128661 - 2¹⁷ = 1748997589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1749128663) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1541875 + ... + 1543008.

Almost surely, 2^1749128661 is an apocalyptic number.

It is an amenable number.

1749128661 is a deficient number, since it is larger than the sum of its proper divisors (1237039051).

1749128661 is an equidigital number, since it uses as much as digits as its factorization.

1749128661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3084902 (or 3084893 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 1749128661 is about 41822.5855370038. The cubic root of 1749128661 is about 1204.8710940313.

The spelling of 1749128661 in words is "one billion, seven hundred forty-nine million, one hundred twenty-eight thousand, six hundred sixty-one".