51642320 has 20 divisors (see below), whose sum is σ = 120068580. Its totient is φ = 20656896.

The previous prime is 51642319. The next prime is 51642341. The reversal of 51642320 is 2324615.

It can be written as a sum of positive squares in 2 ways, for example, as 10784656 + 40857664 = 3284^2 + 6392^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 322685 + ... + 322844.

It is an arithmetic number, because the mean of its divisors is an integer number (6003429).

Almost surely, 2^51642320 is an apocalyptic number.

It is an amenable number.

51642320 is an abundant number, since it is smaller than the sum of its proper divisors (68426260).

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

51642320 is a wasteful number, since it uses less digits than its factorization.

51642320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 645542 (or 645536 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 51642320 is about 7186.2591102743. The cubic root of 51642320 is about 372.3933481437.

Adding to 51642320 its reverse (2324615), we get a palindrome (53966935).

The spelling of 51642320 in words is "fifty-one million, six hundred forty-two thousand, three hundred twenty".