51205920 has 96 divisors (see below), whose sum is σ = 162969408. Its totient is φ = 13513728.

The previous prime is 51205919. The next prime is 51205939. The reversal of 51205920 is 2950215.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50862 + ... + 51858.

It is an arithmetic number, because the mean of its divisors is an integer number (1697598).

Almost surely, 2^51205920 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 51205920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81484704).

51205920 is an abundant number, since it is smaller than the sum of its proper divisors (111763488).

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

51205920 is a wasteful number, since it uses less digits than its factorization.

51205920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1122 (or 1114 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 51205920 is about 7155.8311886181. The cubic root of 51205920 is about 371.3414177030.

It can be divided in two parts, 51205 and 920, that added together give a palindrome (52125).

The spelling of 51205920 in words is "fifty-one million, two hundred five thousand, nine hundred twenty".