1661235265 has 32 divisors (see below), whose sum is σ = 2140934400. Its totient is φ = 1233688320.

The previous prime is 1661235221. The next prime is 1661235269. The reversal of 1661235265 is 5625321661.

It is a de Polignac number, because none of the positive numbers 2^k-1661235265 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661235269) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2543679 + ... + 2544331.

It is an arithmetic number, because the mean of its divisors is an integer number (66904200).

Almost surely, 2^1661235265 is an apocalyptic number.

It is an amenable number.

1661235265 is a deficient number, since it is larger than the sum of its proper divisors (479699135).

1661235265 is a wasteful number, since it uses less digits than its factorization.

1661235265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1177.

The product of its digits is 64800, while the sum is 37.

The square root of 1661235265 is about 40758.2539493536. The cubic root of 1661235265 is about 1184.3417721595.

The spelling of 1661235265 in words is "one billion, six hundred sixty-one million, two hundred thirty-five thousand, two hundred sixty-five".