1665506201 has 16 divisors (see below), whose sum is σ = 1780571520. Its totient is φ = 1552400640.

The previous prime is 1665506191. The next prime is 1665506231. The reversal of 1665506201 is 1026055661.

It is a cyclic number.

It is not a de Polignac number, because 1665506201 - 2²⁶ = 1598397337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1665506231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1490495 + ... + 1491611.

It is an arithmetic number, because the mean of its divisors is an integer number (111285720).

Almost surely, 2^1665506201 is an apocalyptic number.

It is an amenable number.

1665506201 is a deficient number, since it is larger than the sum of its proper divisors (115065319).

1665506201 is a wasteful number, since it uses less digits than its factorization.

1665506201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1904.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 1665506201 is about 40810.6138277777. The cubic root of 1665506201 is about 1185.3558607680.

The spelling of 1665506201 in words is "one billion, six hundred sixty-five million, five hundred six thousand, two hundred one".