1665501061 has 4 divisors (see below), whose sum is σ = 1903429792. Its totient is φ = 1427572332.

The previous prime is 1665501041. The next prime is 1665501077. The reversal of 1665501061 is 1601055661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1601055661 = 173 ⋅9254657.

It is a cyclic number.

It is not a de Polignac number, because 1665501061 - 2⁷ = 1665500933 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 (1665501041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118964355 + ... + 118964368.

It is an arithmetic number, because the mean of its divisors is an integer number (475857448).

Almost surely, 2^1665501061 is an apocalyptic number.

It is an amenable number.

1665501061 is a deficient number, since it is larger than the sum of its proper divisors (237928731).

1665501061 is an equidigital number, since it uses as much as digits as its factorization.

1665501061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237928730.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 1665501061 is about 40810.5508539152. The cubic root of 1665501061 is about 1185.3546413719.

The spelling of 1665501061 in words is "one billion, six hundred sixty-five million, five hundred one thousand, sixty-one".