251223201 has 20 divisors (see below), whose sum is σ = 388228500. Its totient is φ = 161705376.

The previous prime is 251223199. The next prime is 251223209. The reversal of 251223201 is 102322152.

It can be written as a sum of positive squares in 2 ways, for example, as 134583201 + 116640000 = 11601^2 + 10800^2 .

It is not a de Polignac number, because 251223201 - 2¹ = 251223199 is a prime.

It is a super-2 number, since 2×251223201² = 126226193441372802, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (251223209) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 51126 + ... + 55823.

It is an arithmetic number, because the mean of its divisors is an integer number (19411425).

Almost surely, 2^251223201 is an apocalyptic number.

It is an amenable number.

251223201 is a deficient number, since it is larger than the sum of its proper divisors (137005299).

251223201 is a wasteful number, since it uses less digits than its factorization.

251223201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106990 (or 106981 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 251223201 is about 15850.0221135492. The cubic root of 251223201 is about 630.9862782841.

Adding to 251223201 its reverse (102322152), we get a palindrome (353545353).

The spelling of 251223201 in words is "two hundred fifty-one million, two hundred twenty-three thousand, two hundred one".