51161778 has 24 divisors (see below), whose sum is σ = 111024108. Its totient is φ = 17027232.

The previous prime is 51161753. The next prime is 51161779. The reversal of 51161778 is 87716115.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 50594769 + 567009 = 7113^2 + 753^2 .

It is not an unprimeable number, because it can be changed into a prime (51161779) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12076 + ... + 15752.

Almost surely, 2^51161778 is an apocalyptic number.

51161778 is an abundant number, since it is smaller than the sum of its proper divisors (59862330).

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

51161778 is a wasteful number, since it uses less digits than its factorization.

51161778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4458 (or 4455 counting only the distinct ones).

The product of its digits is 11760, while the sum is 36.

The square root of 51161778 is about 7152.7461859065. The cubic root of 51161778 is about 371.2346822235.

The spelling of 51161778 in words is "fifty-one million, one hundred sixty-one thousand, seven hundred seventy-eight".