51221151 has 24 divisors (see below), whose sum is σ = 76215360. Its totient is φ = 33134400.

The previous prime is 51221129. The next prime is 51221167. The reversal of 51221151 is 15112215.

51221151 is a `hidden beast` number, since 512 + 2 + 1 + 151 = 666.

It is not a de Polignac number, because 51221151 - 2⁶ = 51221087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51221101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 42781 + ... + 43961.

It is an arithmetic number, because the mean of its divisors is an integer number (3175640).

Almost surely, 2^51221151 is an apocalyptic number.

51221151 is a deficient number, since it is larger than the sum of its proper divisors (24994209).

51221151 is a wasteful number, since it uses less digits than its factorization.

51221151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1327 (or 1324 counting only the distinct ones).

The product of its digits is 100, while the sum is 18.

The square root of 51221151 is about 7156.8953464474. The cubic root of 51221151 is about 371.3782320691.

Adding to 51221151 its reverse (15112215), we get a palindrome (66333366).

The spelling of 51221151 in words is "fifty-one million, two hundred twenty-one thousand, one hundred fifty-one".