251211101042201 has 4 divisors (see below), whose sum is σ = 251214105432372. Its totient is φ = 251208096652032.

The previous prime is 251211101042173. The next prime is 251211101042207. The reversal of 251211101042201 is 102240101112152.

251211101042201 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 133251930510400 + 117959170531801 = 11543480^2 + 10860901^2 .

It is a cyclic number.

It is not a de Polignac number, because 251211101042201 - 2¹⁴ = 251211101025817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (251211101042207) 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, 1502069660 + ... + 1502236893.

It is an arithmetic number, because the mean of its divisors is an integer number (62803526358093).

Almost surely, 2^{251211101042201} is an apocalyptic number.

It is an amenable number.

251211101042201 is a deficient number, since it is larger than the sum of its proper divisors (3004390171).

251211101042201 is an equidigital number, since it uses as much as digits as its factorization.

251211101042201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3004390170.

The product of its (nonzero) digits is 320, while the sum is 23.

Adding to 251211101042201 its reverse (102240101112152), we get a palindrome (353451202154353).

The spelling of 251211101042201 in words is "two hundred fifty-one trillion, two hundred eleven billion, one hundred one million, forty-two thousand, two hundred one".