51690261 has 16 divisors (see below), whose sum is σ = 78962688. Its totient is φ = 29463600.

The previous prime is 51690179. The next prime is 51690263. The reversal of 51690261 is 16209615.

51690261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51690261 - 2⁹ = 51689749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51690263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6196 + ... + 11906.

It is an arithmetic number, because the mean of its divisors is an integer number (4935168).

Almost surely, 2^51690261 is an apocalyptic number.

It is an amenable number.

51690261 is a deficient number, since it is larger than the sum of its proper divisors (27272427).

51690261 is a wasteful number, since it uses less digits than its factorization.

51690261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6152.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 51690261 is about 7189.5939384641. The cubic root of 51690261 is about 372.5085468663.

Adding to 51690261 its reverse (16209615), we get a palindrome (67899876).

The spelling of 51690261 in words is "fifty-one million, six hundred ninety thousand, two hundred sixty-one".