51020613 has 18 divisors (see below), whose sum is σ = 85729254. Its totient is φ = 29154384.

The previous prime is 51020597. The next prime is 51020617. The reversal of 51020613 is 31602015.

51020613 is a `hidden beast` number, since 51 + 0 + 2 + 0 + 613 = 666.

It can be written as a sum of positive squares in only one way, i.e., 26040609 + 24980004 = 5103^2 + 4998^2 .

It is not a de Polignac number, because 51020613 - 2⁴ = 51020597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51020617) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 57406 + ... + 58287.

Almost surely, 2^51020613 is an apocalyptic number.

It is an amenable number.

51020613 is a deficient number, since it is larger than the sum of its proper divisors (34708641).

51020613 is a wasteful number, since it uses less digits than its factorization.

51020613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115713 (or 115703 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 51020613 is about 7142.8714814142. The cubic root of 51020613 is about 370.8929321988.

Adding to 51020613 its reverse (31602015), we get a palindrome (82622628).

The spelling of 51020613 in words is "fifty-one million, twenty thousand, six hundred thirteen".