51861142 has 4 divisors (see below), whose sum is σ = 77791716. Its totient is φ = 25930570.

The previous prime is 51861119. The next prime is 51861157. The reversal of 51861142 is 24116815.

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

It is a self number, because there is not a number n which added to its sum of digits gives 51861142.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12965284 + ... + 12965287.

It is an arithmetic number, because the mean of its divisors is an integer number (19447929).

Almost surely, 2^51861142 is an apocalyptic number.

51861142 is a deficient number, since it is larger than the sum of its proper divisors (25930574).

51861142 is a wasteful number, since it uses less digits than its factorization.

51861142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25930573.

The product of its digits is 1920, while the sum is 28.

The square root of 51861142 is about 7201.4680447809. The cubic root of 51861142 is about 372.9185829530.

Adding to 51861142 its reverse (24116815), we get a palindrome (75977957).

It can be divided in two parts, 51861 and 142, that added together give a triangular number (52003 = T₃₂₂).

The spelling of 51861142 in words is "fifty-one million, eight hundred sixty-one thousand, one hundred forty-two".