20987503 has 8 divisors (see below), whose sum is σ = 22988880. Its totient is φ = 19071360.

The previous prime is 20987489. The next prime is 20987513. The reversal of 20987503 is 30578902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20987503 - 2⁹ = 20986991 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20987513) 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 7 ways as a sum of consecutive naturals, for example, 20793 + ... + 21778.

It is an arithmetic number, because the mean of its divisors is an integer number (2873610).

Almost surely, 2^20987503 is an apocalyptic number.

20987503 is a deficient number, since it is larger than the sum of its proper divisors (2001377).

20987503 is a wasteful number, since it uses less digits than its factorization.

20987503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42617.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 20987503 is about 4581.2119575501. The cubic root of 20987503 is about 275.8376793572.

The spelling of 20987503 in words is "twenty million, nine hundred eighty-seven thousand, five hundred three".