51781142 has 24 divisors (see below), whose sum is σ = 94285296. Its totient is φ = 21226128.

The previous prime is 51781141. The next prime is 51781157. The reversal of 51781142 is 24118715.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51781141) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9233 + ... + 13740.

It is an arithmetic number, because the mean of its divisors is an integer number (3928554).

Almost surely, 2^51781142 is an apocalyptic number.

51781142 is a deficient number, since it is larger than the sum of its proper divisors (42504154).

51781142 is a wasteful number, since it uses less digits than its factorization.

51781142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23012 (or 23005 counting only the distinct ones).

The product of its digits is 2240, while the sum is 29.

The square root of 51781142 is about 7195.9114780547. The cubic root of 51781142 is about 372.7267319265.

Adding to 51781142 its reverse (24118715), we get a palindrome (75899857).

The spelling of 51781142 in words is "fifty-one million, seven hundred eighty-one thousand, one hundred forty-two".