51311040 has 224 divisors, whose sum is σ = 183465216. Its totient is φ = 12042240.

The previous prime is 51311033. The next prime is 51311041. The reversal of 51311040 is 4011315.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51311041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 454024 + ... + 454136.

Almost surely, 2^51311040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51311040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91732608).

51311040 is an abundant number, since it is smaller than the sum of its proper divisors (132154176).

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

51311040 is a wasteful number, since it uses less digits than its factorization.

51311040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 177 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 51311040 is about 7163.1724815196. The cubic root of 51311040 is about 371.5953514180.

Adding to 51311040 its reverse (4011315), we get a palindrome (55322355).

The spelling of 51311040 in words is "fifty-one million, three hundred eleven thousand, forty".