51511780 has 12 divisors (see below), whose sum is σ = 108174780. Its totient is φ = 20604704.

The previous prime is 51511777. The next prime is 51511783. The reversal of 51511780 is 8711515.

It is an interprime number because it is at equal distance from previous prime (51511777) and next prime (51511783).

It can be written as a sum of positive squares in 2 ways, for example, as 29833444 + 21678336 = 5462^2 + 4656^2 .

It is not an unprimeable number, because it can be changed into a prime (51511783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1287775 + ... + 1287814.

It is an arithmetic number, because the mean of its divisors is an integer number (9014565).

Almost surely, 2^51511780 is an apocalyptic number.

It is an amenable number.

51511780 is an abundant number, since it is smaller than the sum of its proper divisors (56663000).

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

51511780 is a wasteful number, since it uses less digits than its factorization.

51511780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2575598 (or 2575596 counting only the distinct ones).

The product of its (nonzero) digits is 1400, while the sum is 28.

The square root of 51511780 is about 7177.1707517656. The cubic root of 51511780 is about 372.0793082536.

The spelling of 51511780 in words is "fifty-one million, five hundred eleven thousand, seven hundred eighty".