251221530141 has 12 divisors (see below), whose sum is σ = 362923083900. Its totient is φ = 167459078400.

The previous prime is 251221530061. The next prime is 251221530169. The reversal of 251221530141 is 141035122152.

It is a happy number.

251221530141 is a `hidden beast` number, since 2 + 5 + 122 + 1 + 530 + 1 + 4 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 9325764900 + 241895765241 = 96570^2 + 491829^2 .

It is a de Polignac number, because none of the positive numbers 2^k-251221530141 is a prime.

It is a super-2 number, since 2×251221530141² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251221530641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1755810 + ... + 1893491.

It is an arithmetic number, because the mean of its divisors is an integer number (30243590325).

Almost surely, 2^251221530141 is an apocalyptic number.

It is an amenable number.

251221530141 is a deficient number, since it is larger than the sum of its proper divisors (111701553759).

251221530141 is a wasteful number, since it uses less digits than its factorization.

251221530141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3656956 (or 3656953 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

Adding to 251221530141 its reverse (141035122152), we get a palindrome (392256652293).

The spelling of 251221530141 in words is "two hundred fifty-one billion, two hundred twenty-one million, five hundred thirty thousand, one hundred forty-one".