51609140 has 24 divisors (see below), whose sum is σ = 118232352. Its totient is φ = 18766880.

The previous prime is 51609139. The next prime is 51609143. The reversal of 51609140 is 4190615.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51609143) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117074 + ... + 117513.

It is an arithmetic number, because the mean of its divisors is an integer number (4926348).

Almost surely, 2^51609140 is an apocalyptic number.

It is an amenable number.

51609140 is an abundant number, since it is smaller than the sum of its proper divisors (66623212).

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

51609140 is a wasteful number, since it uses less digits than its factorization.

51609140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234607 (or 234605 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 51609140 is about 7183.9501668650. The cubic root of 51609140 is about 372.3135772731.

Adding to 51609140 its reverse (4190615), we get a palindrome (55799755).

The spelling of 51609140 in words is "fifty-one million, six hundred nine thousand, one hundred forty".