51515550 has 36 divisors (see below), whose sum is σ = 138406320. Its totient is φ = 13737360.

The previous prime is 51515549. The next prime is 51515551. The reversal of 51515550 is 5551515.

It is an interprime number because it is at equal distance from previous prime (51515549) and next prime (51515551).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51515551) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 56790 + ... + 57689.

It is an arithmetic number, because the mean of its divisors is an integer number (3844620).

Almost surely, 2^51515550 is an apocalyptic number.

51515550 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

51515550 is an abundant number, since it is smaller than the sum of its proper divisors (86890770).

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

51515550 is a wasteful number, since it uses less digits than its factorization.

51515550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114497 (or 114489 counting only the distinct ones).

The product of its (nonzero) digits is 3125, while the sum is 27.

The square root of 51515550 is about 7177.4333852708. The cubic root of 51515550 is about 372.0883851726.

It can be divided in two parts, 5151 and 5550, that added together give a palindrome (10701).

The spelling of 51515550 in words is "fifty-one million, five hundred fifteen thousand, five hundred fifty".