51649213 has 36 divisors (see below), whose sum is σ = 69249376. Its totient is φ = 37699200.

The previous prime is 51649183. The next prime is 51649219. The reversal of 51649213 is 31294615.

51649213 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-51649213 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51649219) 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 35 ways as a sum of consecutive naturals, for example, 244678 + ... + 244888.

Almost surely, 2^51649213 is an apocalyptic number.

It is an amenable number.

51649213 is a deficient number, since it is larger than the sum of its proper divisors (17600163).

51649213 is a wasteful number, since it uses less digits than its factorization.

51649213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274 (or 246 counting only the distinct ones).

The product of its digits is 6480, while the sum is 31.

The square root of 51649213 is about 7186.7386901153. The cubic root of 51649213 is about 372.4099159066.

It can be divided in two parts, 516 and 49213, that added together give a square (49729 = 223²).

The spelling of 51649213 in words is "fifty-one million, six hundred forty-nine thousand, two hundred thirteen".