51191778 has 16 divisors (see below), whose sum is σ = 111691296. Its totient is φ = 15512640.

The previous prime is 51191773. The next prime is 51191783. The reversal of 51191778 is 87719115.

It is an interprime number because it is at equal distance from previous prime (51191773) and next prime (51191783).

It is not an unprimeable number, because it can be changed into a prime (51191773) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 387751 + ... + 387882.

It is an arithmetic number, because the mean of its divisors is an integer number (6980706).

Almost surely, 2^51191778 is an apocalyptic number.

51191778 is an abundant number, since it is smaller than the sum of its proper divisors (60499518).

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

51191778 is a wasteful number, since it uses less digits than its factorization.

51191778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775649.

The product of its digits is 17640, while the sum is 39.

The square root of 51191778 is about 7154.8429752162. The cubic root of 51191778 is about 371.3072289878.

The spelling of 51191778 in words is "fifty-one million, one hundred ninety-one thousand, seven hundred seventy-eight".