51643020 has 144 divisors (see below), whose sum is σ = 171182592. Its totient is φ = 11531520.

The previous prime is 51642979. The next prime is 51643037. The reversal of 51643020 is 2034615.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 111309 + ... + 111771.

It is an arithmetic number, because the mean of its divisors is an integer number (1188768).

Almost surely, 2^51643020 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51643020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85591296).

51643020 is an abundant number, since it is smaller than the sum of its proper divisors (119539572).

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

51643020 is a wasteful number, since it uses less digits than its factorization.

51643020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512 (or 497 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 51643020 is about 7186.3078141699. The cubic root of 51643020 is about 372.3950307053.

Adding to 51643020 its reverse (2034615), we get a palindrome (53677635).

The spelling of 51643020 in words is "fifty-one million, six hundred forty-three thousand, twenty".