51438940 has 48 divisors (see below), whose sum is σ = 130721472. Its totient is φ = 16598016.

The previous prime is 51438931. The next prime is 51438941. The reversal of 51438940 is 4983415.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 51438896 and 51438905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51438941) 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, 8427 + ... + 13186.

It is an arithmetic number, because the mean of its divisors is an integer number (2723364).

Almost surely, 2^51438940 is an apocalyptic number.

It is an amenable number.

51438940 is an abundant number, since it is smaller than the sum of its proper divisors (79282532).

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

51438940 is a wasteful number, since it uses less digits than its factorization.

51438940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21646 (or 21644 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 51438940 is about 7172.0945336770. The cubic root of 51438940 is about 371.9038465018.

The spelling of 51438940 in words is "fifty-one million, four hundred thirty-eight thousand, nine hundred forty".