1665116501 has 2 divisors, whose sum is σ = 1665116502. Its totient is φ = 1665116500.

The previous prime is 1665116491. The next prime is 1665116549. The reversal of 1665116501 is 1056115661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1230185476 + 434931025 = 35074^2 + 20855^2 .

It is an emirp because it is prime and its reverse (1056115661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1665116501 is a prime.

It is a super-2 number, since 2×1665116501² = 5545225923804966002, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665146501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832558250 + 832558251.

It is an arithmetic number, because the mean of its divisors is an integer number (832558251).

Almost surely, 2^1665116501 is an apocalyptic number.

It is an amenable number.

1665116501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665116501 is an equidigital number, since it uses as much as digits as its factorization.

1665116501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 1665116501 is about 40805.8390552137. The cubic root of 1665116501 is about 1185.2634025489.

The spelling of 1665116501 in words is "one billion, six hundred sixty-five million, one hundred sixteen thousand, five hundred one".