51647820 has 48 divisors (see below), whose sum is σ = 165274368. Its totient is φ = 11805120.

The previous prime is 51647801. The next prime is 51647831. The reversal of 51647820 is 2874615.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61066 + ... + 61905.

It is an arithmetic number, because the mean of its divisors is an integer number (3443216).

Almost surely, 2^51647820 is an apocalyptic number.

It is an amenable number.

51647820 is an abundant number, since it is smaller than the sum of its proper divisors (113626548).

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

51647820 is a wasteful number, since it uses less digits than its factorization.

51647820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122990 (or 122988 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 51647820 is about 7186.6417748487. The cubic root of 51647820 is about 372.4065678616.

The spelling of 51647820 in words is "fifty-one million, six hundred forty-seven thousand, eight hundred twenty".