51659820 has 36 divisors (see below), whose sum is σ = 156702000. Its totient is φ = 13775904.

The previous prime is 51659809. The next prime is 51659831. The reversal of 51659820 is 2895615.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (51659809) and next prime (51659831).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 143320 + ... + 143679.

Almost surely, 2^51659820 is an apocalyptic number.

It is an amenable number.

51659820 is an abundant number, since it is smaller than the sum of its proper divisors (105042180).

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

51659820 is a wasteful number, since it uses less digits than its factorization.

51659820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287014 (or 287009 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 51659820 is about 7187.4766086576. The cubic root of 51659820 is about 372.4354076252.

The spelling of 51659820 in words is "fifty-one million, six hundred fifty-nine thousand, eight hundred twenty".