51217540 has 48 divisors (see below), whose sum is σ = 123520320. Its totient is φ = 17642880.

The previous prime is 51217531. The next prime is 51217541. The reversal of 51217540 is 4571215.

It is not an unprimeable number, because it can be changed into a prime (51217541) 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, 1947 + ... + 10306.

It is an arithmetic number, because the mean of its divisors is an integer number (2573340).

Almost surely, 2^51217540 is an apocalyptic number.

It is an amenable number.

51217540 is an abundant number, since it is smaller than the sum of its proper divisors (72302780).

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

51217540 is a wasteful number, since it uses less digits than its factorization.

51217540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12292 (or 12290 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 51217540 is about 7156.6430678077. The cubic root of 51217540 is about 371.3695046958.

Adding to 51217540 its reverse (4571215), we get a palindrome (55788755).

It can be divided in two parts, 512175 and 40, that added together give a palindrome (512215).

The spelling of 51217540 in words is "fifty-one million, two hundred seventeen thousand, five hundred forty".