51249181 has 4 divisors (see below), whose sum is σ = 52634332. Its totient is φ = 49864032.

The previous prime is 51249179. The next prime is 51249193. The reversal of 51249181 is 18194215.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 31304025 + 19945156 = 5595^2 + 4466^2 .

It is a cyclic number.

It is not a de Polignac number, because 51249181 - 2¹ = 51249179 is a prime.

It is a super-2 number, since 2×51249181² = 5252957106341522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51249131) 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, 692520 + ... + 692593.

It is an arithmetic number, because the mean of its divisors is an integer number (13158583).

Almost surely, 2^51249181 is an apocalyptic number.

It is an amenable number.

51249181 is a deficient number, since it is larger than the sum of its proper divisors (1385151).

51249181 is a wasteful number, since it uses less digits than its factorization.

51249181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1385150.

The product of its digits is 2880, while the sum is 31.

The square root of 51249181 is about 7158.8533299684. The cubic root of 51249181 is about 371.4459634220.

The spelling of 51249181 in words is "fifty-one million, two hundred forty-nine thousand, one hundred eighty-one".