51240620 has 12 divisors (see below), whose sum is σ = 107605344. Its totient is φ = 20496240.

The previous prime is 51240589. The next prime is 51240643. The reversal of 51240620 is 2604215.

It is a happy number.

It is a super-2 number, since 2×51240620² = 5251202275968800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 2562031 = 51240620 / (5 + 1 + 2 + 4 + 0 + 6 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 51240592 and 51240601.

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, 1280996 + ... + 1281035.

It is an arithmetic number, because the mean of its divisors is an integer number (8967112).

Almost surely, 2^51240620 is an apocalyptic number.

It is an amenable number.

51240620 is an abundant number, since it is smaller than the sum of its proper divisors (56364724).

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

51240620 is a wasteful number, since it uses less digits than its factorization.

51240620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2562040 (or 2562038 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 51240620 is about 7158.2553740419. The cubic root of 51240620 is about 371.4252793453.

Adding to 51240620 its reverse (2604215), we get a palindrome (53844835).

The spelling of 51240620 in words is "fifty-one million, two hundred forty thousand, six hundred twenty".