1661667265 has 8 divisors (see below), whose sum is σ = 1994529600. Its totient is φ = 1328981232.

The previous prime is 1661667257. The next prime is 1661667341. The reversal of 1661667265 is 5627661661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1661667265 - 2³ = 1661667257 is a prime.

It is a super-2 number, since 2×1661667265² = 5522276199145160450, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22365 + ... + 61834.

It is an arithmetic number, because the mean of its divisors is an integer number (249316200).

Almost surely, 2^1661667265 is an apocalyptic number.

It is an amenable number.

1661667265 is a deficient number, since it is larger than the sum of its proper divisors (332862335).

1661667265 is an equidigital number, since it uses as much as digits as its factorization.

1661667265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88151.

The product of its digits is 544320, while the sum is 46.

The square root of 1661667265 is about 40763.5531449357. The cubic root of 1661667265 is about 1184.4444249491. Note that the first 4 decimals are identical.

The spelling of 1661667265 in words is "one billion, six hundred sixty-one million, six hundred sixty-seven thousand, two hundred sixty-five".