201664651 has 4 divisors (see below), whose sum is σ = 212278600. Its totient is φ = 191050704.

The previous prime is 201664633. The next prime is 201664663. The reversal of 201664651 is 156466102.

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

It is a cyclic number.

It is not a de Polignac number, because 201664651 - 2²⁵ = 168110219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201664601) 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, 5306946 + ... + 5306983.

It is an arithmetic number, because the mean of its divisors is an integer number (53069650).

Almost surely, 2^201664651 is an apocalyptic number.

201664651 is a deficient number, since it is larger than the sum of its proper divisors (10613949).

201664651 is a wasteful number, since it uses less digits than its factorization.

201664651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10613948.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 201664651 is about 14200.8679664308. The cubic root of 201664651 is about 586.4215565615.

The spelling of 201664651 in words is "two hundred one million, six hundred sixty-four thousand, six hundred fifty-one".