51545640 has 32 divisors (see below), whose sum is σ = 154637280. Its totient is φ = 13745472.

The previous prime is 51545639. The next prime is 51545647. The reversal of 51545640 is 4654515.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 51545598 and 51545607.

It is not an unprimeable number, because it can be changed into a prime (51545647) 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, 214654 + ... + 214893.

It is an arithmetic number, because the mean of its divisors is an integer number (4832415).

Almost surely, 2^51545640 is an apocalyptic number.

It is an amenable number.

51545640 is an abundant number, since it is smaller than the sum of its proper divisors (103091640).

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

51545640 is a wasteful number, since it uses less digits than its factorization.

51545640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429561 (or 429557 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 51545640 is about 7179.5292324776. The cubic root of 51545640 is about 372.1608161205.

The spelling of 51545640 in words is "fifty-one million, five hundred forty-five thousand, six hundred forty".