51717780 has 36 divisors (see below), whose sum is σ = 156877812. Its totient is φ = 13791360.

The previous prime is 51717773. The next prime is 51717793. The reversal of 51717780 is 8771715.

It can be written as a sum of positive squares in 2 ways, for example, as 40985604 + 10732176 = 6402^2 + 3276^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 143481 + ... + 143840.

It is an arithmetic number, because the mean of its divisors is an integer number (4357717).

Almost surely, 2^51717780 is an apocalyptic number.

It is an amenable number.

51717780 is an abundant number, since it is smaller than the sum of its proper divisors (105160032).

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

51717780 is a wasteful number, since it uses less digits than its factorization.

51717780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287336 (or 287331 counting only the distinct ones).

The product of its (nonzero) digits is 13720, while the sum is 36.

The square root of 51717780 is about 7191.5074914791. The cubic root of 51717780 is about 372.5746408389.

The spelling of 51717780 in words is "fifty-one million, seven hundred seventeen thousand, seven hundred eighty".