51645420 has 72 divisors (see below), whose sum is σ = 164913840. Its totient is φ = 13046400.

The previous prime is 51645413. The next prime is 51645421. The reversal of 51645420 is 2454615.

It is not an unprimeable number, because it can be changed into a prime (51645421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4131 + ... + 10970.

It is an arithmetic number, because the mean of its divisors is an integer number (2290470).

Almost surely, 2^51645420 is an apocalyptic number.

It is an amenable number.

51645420 is an abundant number, since it is smaller than the sum of its proper divisors (113268420).

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

51645420 is a wasteful number, since it uses less digits than its factorization.

51645420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15135 (or 15130 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 51645420 is about 7186.4747964492. The cubic root of 51645420 is about 372.4007993728.

The spelling of 51645420 in words is "fifty-one million, six hundred forty-five thousand, four hundred twenty".