51515151 has 32 divisors (see below), whose sum is σ = 74996928. Its totient is φ = 31334400.

The previous prime is 51515129. The next prime is 51515159. The reversal of 51515151 is 15151515.

It is not a de Polignac number, because 51515151 - 2¹⁵ = 51482383 is a prime.

51515151 is an undulating number in base 10.

51515151 is a modest number, since divided by 515151 gives 51 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51515159) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 375955 + ... + 376091.

It is an arithmetic number, because the mean of its divisors is an integer number (2343654).

Almost surely, 2^51515151 is an apocalyptic number.

51515151 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

51515151 is a deficient number, since it is larger than the sum of its proper divisors (23481777).

51515151 is a wasteful number, since it uses less digits than its factorization.

51515151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331.

The product of its digits is 625, while the sum is 24.

The square root of 51515151 is about 7177.4055897657. The cubic root of 51515151 is about 372.0874245329.

Adding to 51515151 its reverse (15151515), we get a palindrome (66666666).

The spelling of 51515151 in words is "fifty-one million, five hundred fifteen thousand, one hundred fifty-one".