201023639 has 4 divisors (see below), whose sum is σ = 201053424. Its totient is φ = 200993856.

The previous prime is 201023597. The next prime is 201023663. The reversal of 201023639 is 936320102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 936320102 = 2 ⋅468160051.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201023639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201023689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 614 + ... + 20060.

It is an arithmetic number, because the mean of its divisors is an integer number (50263356).

Almost surely, 2^201023639 is an apocalyptic number.

201023639 is a deficient number, since it is larger than the sum of its proper divisors (29785).

201023639 is a wasteful number, since it uses less digits than its factorization.

201023639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29784.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 201023639 is about 14178.2805374982. The cubic root of 201023639 is about 585.7995631676.

The spelling of 201023639 in words is "two hundred one million, twenty-three thousand, six hundred thirty-nine".