20409937 has 4 divisors (see below), whose sum is σ = 20419056. Its totient is φ = 20400820.

The previous prime is 20409919. The next prime is 20409941. The reversal of 20409937 is 73990402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20409937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20409967) 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, 1362 + ... + 6532.

It is an arithmetic number, because the mean of its divisors is an integer number (5104764).

Almost surely, 2^20409937 is an apocalyptic number.

It is an amenable number.

20409937 is a deficient number, since it is larger than the sum of its proper divisors (9119).

20409937 is an equidigital number, since it uses as much as digits as its factorization.

20409937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9118.

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 20409937 is about 4517.7358267167. The cubic root of 20409937 is about 273.2838000995.

The spelling of 20409937 in words is "twenty million, four hundred nine thousand, nine hundred thirty-seven".