51172561 has 8 divisors (see below), whose sum is σ = 55972800. Its totient is φ = 46397040.

The previous prime is 51172553. The next prime is 51172573. The reversal of 51172561 is 16527115.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51172561 - 2³ = 51172553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51172531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1701 + ... + 10258.

It is an arithmetic number, because the mean of its divisors is an integer number (6996600).

Almost surely, 2^51172561 is an apocalyptic number.

It is an amenable number.

51172561 is a deficient number, since it is larger than the sum of its proper divisors (4800239).

51172561 is a wasteful number, since it uses less digits than its factorization.

51172561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12359.

The product of its digits is 2100, while the sum is 28.

The square root of 51172561 is about 7153.4999126302. The cubic root of 51172561 is about 371.2607612128.

Adding to 51172561 its reverse (16527115), we get a palindrome (67699676).

The spelling of 51172561 in words is "fifty-one million, one hundred seventy-two thousand, five hundred sixty-one".