51649460 has 24 divisors (see below), whose sum is σ = 109022760. Its totient is φ = 20553344.

The previous prime is 51649439. The next prime is 51649469. The reversal of 51649460 is 6494615.

It can be written as a sum of positive squares in 4 ways, for example, as 15697444 + 35952016 = 3962^2 + 5996^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 51649460.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51649469) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2615 + ... + 10494.

It is an arithmetic number, because the mean of its divisors is an integer number (4542615).

Almost surely, 2^51649460 is an apocalyptic number.

It is an amenable number.

51649460 is an abundant number, since it is smaller than the sum of its proper divisors (57373300).

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

51649460 is a wasteful number, since it uses less digits than its factorization.

51649460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13315 (or 13313 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 51649460 is about 7186.7558745236. The cubic root of 51649460 is about 372.4105095594.

The spelling of 51649460 in words is "fifty-one million, six hundred forty-nine thousand, four hundred sixty".