20513519 has 4 divisors (see below), whose sum is σ = 22091496. Its totient is φ = 18935544.

The previous prime is 20513513. The next prime is 20513531. The reversal of 20513519 is 91531502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20513519 is a prime.

It is a super-2 number, since 2×20513519² = 841608923526722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20513513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 788969 + ... + 788994.

It is an arithmetic number, because the mean of its divisors is an integer number (5522874).

Almost surely, 2^20513519 is an apocalyptic number.

20513519 is a deficient number, since it is larger than the sum of its proper divisors (1577977).

20513519 is a wasteful number, since it uses less digits than its factorization.

20513519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1577976.

The product of its (nonzero) digits is 1350, while the sum is 26.

The square root of 20513519 is about 4529.1852468187. The cubic root of 20513519 is about 273.7453323085.

The spelling of 20513519 in words is "twenty million, five hundred thirteen thousand, five hundred nineteen".