51909789 has 24 divisors (see below), whose sum is σ = 74691072. Its totient is φ = 31956480.

The previous prime is 51909787. The next prime is 51909839. The reversal of 51909789 is 98790915.

51909789 = 807² + 808² + ... + 879².

It is not a de Polignac number, because 51909789 - 2¹ = 51909787 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51909787) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 271684 + ... + 271874.

It is an arithmetic number, because the mean of its divisors is an integer number (3112128).

Almost surely, 2^51909789 is an apocalyptic number.

It is an amenable number.

51909789 is a deficient number, since it is larger than the sum of its proper divisors (22781283).

51909789 is a wasteful number, since it uses less digits than its factorization.

51909789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357 (or 284 counting only the distinct ones).

The product of its (nonzero) digits is 204120, while the sum is 48.

The square root of 51909789 is about 7204.8448283082. The cubic root of 51909789 is about 373.0351487169.

The spelling of 51909789 in words is "fifty-one million, nine hundred nine thousand, seven hundred eighty-nine".