1665509610 has 16 divisors (see below), whose sum is σ = 3997223136. Its totient is φ = 444135888.

The previous prime is 1665509609. The next prime is 1665509611. The reversal of 1665509610 is 169055661.

It is an interprime number because it is at equal distance from previous prime (1665509609) and next prime (1665509611).

It is a super-2 number, since 2×1665509610² = 5547844522004704200, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1665509611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27758464 + ... + 27758523.

It is an arithmetic number, because the mean of its divisors is an integer number (249826446).

Almost surely, 2^1665509610 is an apocalyptic number.

1665509610 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1665509610 is an abundant number, since it is smaller than the sum of its proper divisors (2331713526).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1665509610 is a wasteful number, since it uses less digits than its factorization.

1665509610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55516997.

The product of its (nonzero) digits is 48600, while the sum is 39.

The square root of 1665509610 is about 40810.6555938520. The cubic root of 1665509610 is about 1185.3566695062.

It can be divided in two parts, 16655096 and 10, that added together give a triangular number (16655106 = T₅₇₇₁).

The spelling of 1665509610 in words is "one billion, six hundred sixty-five million, five hundred nine thousand, six hundred ten".