20391937 has 8 divisors (see below), whose sum is σ = 20915712. Its totient is φ = 19872000.

The previous prime is 20391929. The next prime is 20391967. The reversal of 20391937 is 73919302.

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 20391937 - 2³ = 20391929 is a prime.

It is a super-2 number, since 2×20391937² = 831662189223938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20391907) 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, 11937 + ... + 13537.

It is an arithmetic number, because the mean of its divisors is an integer number (2614464).

Almost surely, 2^20391937 is an apocalyptic number.

It is an amenable number.

20391937 is a deficient number, since it is larger than the sum of its proper divisors (523775).

20391937 is a wasteful number, since it uses less digits than its factorization.

20391937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1919.

The product of its (nonzero) digits is 10206, while the sum is 34.

The square root of 20391937 is about 4515.7432389364. The cubic root of 20391937 is about 273.2034380157.

The spelling of 20391937 in words is "twenty million, three hundred ninety-one thousand, nine hundred thirty-seven".