51021313 has 4 divisors (see below), whose sum is σ = 58310080. Its totient is φ = 43732548.

The previous prime is 51021307. The next prime is 51021323. The reversal of 51021313 is 31312015.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51021313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51021323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3644373 + ... + 3644386.

It is an arithmetic number, because the mean of its divisors is an integer number (14577520).

Almost surely, 2^51021313 is an apocalyptic number.

It is an amenable number.

51021313 is a deficient number, since it is larger than the sum of its proper divisors (7288767).

51021313 is an equidigital number, since it uses as much as digits as its factorization.

51021313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7288766.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 51021313 is about 7142.9204811477. The cubic root of 51021313 is about 370.8946284013.

Adding to 51021313 its reverse (31312015), we get a palindrome (82333328).

The spelling of 51021313 in words is "fifty-one million, twenty-one thousand, three hundred thirteen".