513513021 has 16 divisors (see below), whose sum is σ = 786211328. Its totient is φ = 292042800.

The previous prime is 513513017. The next prime is 513513029. The reversal of 513513021 is 120315315.

It is not a de Polignac number, because 513513021 - 2² = 513513017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (513513029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53515 + ... + 62376.

It is an arithmetic number, because the mean of its divisors is an integer number (49138208).

Almost surely, 2^513513021 is an apocalyptic number.

It is an amenable number.

513513021 is a deficient number, since it is larger than the sum of its proper divisors (272698307).

513513021 is a wasteful number, since it uses less digits than its factorization.

513513021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116112.

The product of its (nonzero) digits is 450, while the sum is 21.

The square root of 513513021 is about 22660.8256910467. The cubic root of 513513021 is about 800.7872568001.

Adding to 513513021 its reverse (120315315), we get a palindrome (633828336).

The spelling of 513513021 in words is "five hundred thirteen million, five hundred thirteen thousand, twenty-one".