66201649 has 4 divisors (see below), whose sum is σ = 66820464. Its totient is φ = 65582836.

The previous prime is 66201631. The next prime is 66201677. The reversal of 66201649 is 94610266.

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: 94610266 = 2 ⋅47305133.

It is a cyclic number.

It is not a de Polignac number, because 66201649 - 2¹⁵ = 66168881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66201679) 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, 309247 + ... + 309460.

It is an arithmetic number, because the mean of its divisors is an integer number (16705116).

Almost surely, 2^66201649 is an apocalyptic number.

It is an amenable number.

66201649 is a deficient number, since it is larger than the sum of its proper divisors (618815).

66201649 is a wasteful number, since it uses less digits than its factorization.

66201649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618814.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 66201649 is about 8136.4395776040. The cubic root of 66201649 is about 404.5351553372.

The spelling of 66201649 in words is "sixty-six million, two hundred one thousand, six hundred forty-nine".