51001211251 has 4 divisors (see below), whose sum is σ = 51526997032. Its totient is φ = 50475425472.

The previous prime is 51001211227. The next prime is 51001211257. The reversal of 51001211251 is 15211210015.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15211210015 = 5 ⋅3042242003.

It is a cyclic number.

It is not a de Polignac number, because 51001211251 - 2⁷ = 51001211123 is a prime.

It is a super-2 number, since 2×51001211251² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51001211257) 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, 262892745 + ... + 262892938.

It is an arithmetic number, because the mean of its divisors is an integer number (12881749258).

Almost surely, 2^51001211251 is an apocalyptic number.

51001211251 is a deficient number, since it is larger than the sum of its proper divisors (525785781).

51001211251 is an equidigital number, since it uses as much as digits as its factorization.

51001211251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525785780.

The product of its (nonzero) digits is 100, while the sum is 19.

Adding to 51001211251 its reverse (15211210015), we get a palindrome (66212421266).

The spelling of 51001211251 in words is "fifty-one billion, one million, two hundred eleven thousand, two hundred fifty-one".