20493509 has 8 divisors (see below), whose sum is σ = 20942592. Its totient is φ = 20049120.

The previous prime is 20493503. The next prime is 20493521. The reversal of 20493509 is 90539402.

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 20493509 - 2⁴ = 20493493 is a prime.

It is a super-2 number, since 2×20493509² = 839967822266162, 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 (20493503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8492 + ... + 10634.

It is an arithmetic number, because the mean of its divisors is an integer number (2617824).

Almost surely, 2^20493509 is an apocalyptic number.

It is an amenable number.

20493509 is a deficient number, since it is larger than the sum of its proper divisors (449083).

20493509 is a wasteful number, since it uses less digits than its factorization.

20493509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2347.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 20493509 is about 4526.9757012823. The cubic root of 20493509 is about 273.6562946658.

The spelling of 20493509 in words is "twenty million, four hundred ninety-three thousand, five hundred nine".