51645061 has 4 divisors (see below), whose sum is σ = 55617772. Its totient is φ = 47672352.

The previous prime is 51645053. The next prime is 51645071. The reversal of 51645061 is 16054615.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 29224836 + 22420225 = 5406^2 + 4735^2 .

It is not a de Polignac number, because 51645061 - 2³ = 51645053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51645071) 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, 1986336 + ... + 1986361.

It is an arithmetic number, because the mean of its divisors is an integer number (13904443).

Almost surely, 2^51645061 is an apocalyptic number.

It is an amenable number.

51645061 is a deficient number, since it is larger than the sum of its proper divisors (3972711).

51645061 is a wasteful number, since it uses less digits than its factorization.

51645061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3972710.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 51645061 is about 7186.4498189301. The cubic root of 51645061 is about 372.3999364877.

Adding to 51645061 its reverse (16054615), we get a palindrome (67699676).

The spelling of 51645061 in words is "fifty-one million, six hundred forty-five thousand, sixty-one".