20513919 has 4 divisors (see below), whose sum is σ = 27351896. Its totient is φ = 13675944.

The previous prime is 20513903. The next prime is 20513921. The reversal of 20513919 is 91931502.

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

It is not a de Polignac number, because 20513919 - 2⁴ = 20513903 is a prime.

It is a super-2 number, since 2×20513919² = 841641745477122, 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 (20513989) 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, 3418984 + ... + 3418989.

It is an arithmetic number, because the mean of its divisors is an integer number (6837974).

Almost surely, 2^20513919 is an apocalyptic number.

20513919 is a deficient number, since it is larger than the sum of its proper divisors (6837977).

20513919 is an equidigital number, since it uses as much as digits as its factorization.

20513919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6837976.

The product of its (nonzero) digits is 2430, while the sum is 30.

The square root of 20513919 is about 4529.2294046559. The cubic root of 20513919 is about 273.7471115810.

The spelling of 20513919 in words is "twenty million, five hundred thirteen thousand, nine hundred nineteen".