20513603 has 4 divisors (see below), whose sum is σ = 22378488. Its totient is φ = 18648720.

The previous prime is 20513593. The next prime is 20513621. The reversal of 20513603 is 30631502.

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

It is a cyclic number.

It is not a de Polignac number, because 20513603 - 2⁴ = 20513587 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20513303) 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, 932426 + ... + 932447.

It is an arithmetic number, because the mean of its divisors is an integer number (5594622).

Almost surely, 2^20513603 is an apocalyptic number.

20513603 is a deficient number, since it is larger than the sum of its proper divisors (1864885).

20513603 is a wasteful number, since it uses less digits than its factorization.

20513603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1864884.

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 20513603 is about 4529.1945200002. The cubic root of 20513603 is about 273.7457059577.

The spelling of 20513603 in words is "twenty million, five hundred thirteen thousand, six hundred three".