51040040 has 16 divisors (see below), whose sum is σ = 114840180. Its totient is φ = 20416000.

The previous prime is 51040037. The next prime is 51040051. The reversal of 51040040 is 4004015.

It can be written as a sum of positive squares in 2 ways, for example, as 45995524 + 5044516 = 6782^2 + 2246^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51039997 and 51040024.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 637961 + ... + 638040.

Almost surely, 2^51040040 is an apocalyptic number.

It is an amenable number.

51040040 is an abundant number, since it is smaller than the sum of its proper divisors (63800140).

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

51040040 is a wasteful number, since it uses less digits than its factorization.

51040040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1276012 (or 1276008 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 51040040 is about 7144.2312392587. The cubic root of 51040040 is about 370.9400009046.

Adding to 51040040 its reverse (4004015), we get a palindrome (55044055).

The spelling of 51040040 in words is "fifty-one million, forty thousand, forty".