51403440 has 80 divisors (see below), whose sum is σ = 173846016. Its totient is φ = 12460800.

The previous prime is 51403439. The next prime is 51403441. The reversal of 51403440 is 4430415.

It is an interprime number because it is at equal distance from previous prime (51403439) and next prime (51403441).

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (51403441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7096 + ... + 12375.

Almost surely, 2^51403440 is an apocalyptic number.

It is an amenable number.

51403440 is an abundant number, since it is smaller than the sum of its proper divisors (122442576).

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

51403440 is a wasteful number, since it uses less digits than its factorization.

51403440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19498 (or 19492 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 51403440 is about 7169.6192367517. The cubic root of 51403440 is about 371.8182717412.

Adding to 51403440 its reverse (4430415), we get a palindrome (55833855).

The spelling of 51403440 in words is "fifty-one million, four hundred three thousand, four hundred forty".