51491061 has 24 divisors (see below), whose sum is σ = 75986456. Its totient is φ = 33592320.

The previous prime is 51491059. The next prime is 51491101. The reversal of 51491061 is 16019415.

51491061 is a `hidden beast` number, since 514 + 91 + 0 + 61 = 666.

51491061 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 938961 + 50552100 = 969^2 + 7110^2 .

It is not a de Polignac number, because 51491061 - 2¹ = 51491059 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51492061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 118701 + ... + 119133.

Almost surely, 2^51491061 is an apocalyptic number.

It is an amenable number.

51491061 is a deficient number, since it is larger than the sum of its proper divisors (24495395).

51491061 is a wasteful number, since it uses less digits than its factorization.

51491061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 693 (or 690 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 51491061 is about 7175.7272105341. The cubic root of 51491061 is about 372.0294158147.

The spelling of 51491061 in words is "fifty-one million, four hundred ninety-one thousand, sixty-one".