3721535666 has 4 divisors (see below), whose sum is σ = 5582303502. Its totient is φ = 1860767832.

The previous prime is 3721535627. The next prime is 3721535687. The reversal of 3721535666 is 6665351273.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 2472973441 + 1248562225 = 49729^2 + 35335^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 930383915 + ... + 930383918.

Almost surely, 2^3721535666 is an apocalyptic number.

3721535666 is a deficient number, since it is larger than the sum of its proper divisors (1860767836).

3721535666 is a wasteful number, since it uses less digits than its factorization.

3721535666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1860767835.

The product of its digits is 680400, while the sum is 44.

The square root of 3721535666 is about 61004.3905469106. The cubic root of 3721535666 is about 1549.6753626047.

The spelling of 3721535666 in words is "three billion, seven hundred twenty-one million, five hundred thirty-five thousand, six hundred sixty-six".