51809146 has 4 divisors (see below), whose sum is σ = 77713722. Its totient is φ = 25904572.

The previous prime is 51809141. The next prime is 51809171. The reversal of 51809146 is 64190815.

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

It can be written as a sum of positive squares in only one way, i.e., 50623225 + 1185921 = 7115^2 + 1089^2 .

It is not an unprimeable number, because it can be changed into a prime (51809141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12952285 + ... + 12952288.

Almost surely, 2^51809146 is an apocalyptic number.

51809146 is a deficient number, since it is larger than the sum of its proper divisors (25904576).

51809146 is a wasteful number, since it uses less digits than its factorization.

51809146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25904575.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 51809146 is about 7197.8570422036. The cubic root of 51809146 is about 372.7939118425.

The spelling of 51809146 in words is "fifty-one million, eight hundred nine thousand, one hundred forty-six".