51260721 has 8 divisors (see below), whose sum is σ = 71319360. Its totient is φ = 32687952.

The previous prime is 51260681. The next prime is 51260723. The reversal of 51260721 is 12706215.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 51260721 - 2¹⁴ = 51244337 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51260691 and 51260700.

It is not an unprimeable number, because it can be changed into a prime (51260723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 371386 + ... + 371523.

It is an arithmetic number, because the mean of its divisors is an integer number (8914920).

Almost surely, 2^51260721 is an apocalyptic number.

It is an amenable number.

51260721 is a deficient number, since it is larger than the sum of its proper divisors (20058639).

51260721 is a wasteful number, since it uses less digits than its factorization.

51260721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 742935.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 51260721 is about 7159.6592796026. The cubic root of 51260721 is about 371.4738413617.

Adding to 51260721 its reverse (12706215), we get a palindrome (63966936).

The spelling of 51260721 in words is "fifty-one million, two hundred sixty thousand, seven hundred twenty-one".