51440403 has 16 divisors (see below), whose sum is σ = 81089280. Its totient is φ = 28380576.

The previous prime is 51440393. The next prime is 51440437. The reversal of 51440403 is 30404415.

It is not a de Polignac number, because 51440403 - 2⁴ = 51440387 is a prime.

It is a super-2 number, since 2×51440403² = 5292230121604818, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 51440403.

It is not an unprimeable number, because it can be changed into a prime (51440003) 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, 41625 + ... + 42842.

It is an arithmetic number, because the mean of its divisors is an integer number (5068080).

Almost surely, 2^51440403 is an apocalyptic number.

51440403 is a deficient number, since it is larger than the sum of its proper divisors (29648877).

51440403 is a wasteful number, since it uses less digits than its factorization.

51440403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84506.

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

The square root of 51440403 is about 7172.1965254725. The cubic root of 51440403 is about 371.9073723013.

Adding to 51440403 its reverse (30404415), we get a palindrome (81844818).

The spelling of 51440403 in words is "fifty-one million, four hundred forty thousand, four hundred three".