51311442 has 48 divisors (see below), whose sum is σ = 127016640. Its totient is φ = 13530816.

The previous prime is 51311441. The next prime is 51311453. The reversal of 51311442 is 24411315.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (51311441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3484 + ... + 10712.

It is an arithmetic number, because the mean of its divisors is an integer number (2646180).

Almost surely, 2^51311442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51311442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63508320).

51311442 is an abundant number, since it is smaller than the sum of its proper divisors (75705198).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51311442 is a wasteful number, since it uses less digits than its factorization.

51311442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7267 (or 7254 counting only the distinct ones).

The product of its digits is 480, while the sum is 21.

The square root of 51311442 is about 7163.2005416573. The cubic root of 51311442 is about 371.5963218456.

Adding to 51311442 its reverse (24411315), we get a palindrome (75722757).

The spelling of 51311442 in words is "fifty-one million, three hundred eleven thousand, four hundred forty-two".