513513031421 has 4 divisors (see below), whose sum is σ = 553014033852. Its totient is φ = 474012028992.

The previous prime is 513513031393. The next prime is 513513031429. The reversal of 513513031421 is 124130315315.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 124130315315 = 5 ⋅24826063063.

It can be written as a sum of positive squares in 2 ways, for example, as 27823908025 + 485689123396 = 166805^2 + 696914^2 .

It is a cyclic number.

It is not a de Polignac number, because 513513031421 - 2³⁰ = 512439289597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (513513031429) 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, 19750501196 + ... + 19750501221.

It is an arithmetic number, because the mean of its divisors is an integer number (138253508463).

Almost surely, 2^513513031421 is an apocalyptic number.

It is an amenable number.

513513031421 is a deficient number, since it is larger than the sum of its proper divisors (39501002431).

513513031421 is a wasteful number, since it uses less digits than its factorization.

513513031421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39501002430.

The product of its (nonzero) digits is 5400, while the sum is 29.

Adding to 513513031421 its reverse (124130315315), we get a palindrome (637643346736).

The spelling of 513513031421 in words is "five hundred thirteen billion, five hundred thirteen million, thirty-one thousand, four hundred twenty-one".