201155721 has 16 divisors (see below), whose sum is σ = 293737920. Its totient is φ = 121688640.

The previous prime is 201155719. The next prime is 201155749. The reversal of 201155721 is 127551102.

It is not a de Polignac number, because 201155721 - 2¹ = 201155719 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 201155691 and 201155700.

It is not an unprimeable number, because it can be changed into a prime (201155701) 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, 41410 + ... + 46011.

It is an arithmetic number, because the mean of its divisors is an integer number (18358620).

Almost surely, 2^201155721 is an apocalyptic number.

It is an amenable number.

201155721 is a deficient number, since it is larger than the sum of its proper divisors (92582199).

201155721 is a wasteful number, since it uses less digits than its factorization.

201155721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87496.

The product of its (nonzero) digits is 700, while the sum is 24.

The square root of 201155721 is about 14182.9376717237. The cubic root of 201155721 is about 585.9278343806.

The spelling of 201155721 in words is "two hundred one million, one hundred fifty-five thousand, seven hundred twenty-one".