20689837 has 8 divisors (see below), whose sum is σ = 24195776. Its totient is φ = 17321472.

The previous prime is 20689829. The next prime is 20689849. The reversal of 20689837 is 73898602.

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

It is not a de Polignac number, because 20689837 - 2³ = 20689829 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20689793 and 20689802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20689807) 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, 34068 + ... + 34669.

It is an arithmetic number, because the mean of its divisors is an integer number (3024472).

Almost surely, 2^20689837 is an apocalyptic number.

It is an amenable number.

20689837 is a deficient number, since it is larger than the sum of its proper divisors (3505939).

20689837 is an equidigital number, since it uses as much as digits as its factorization.

20689837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68787.

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 20689837 is about 4548.6082486844. The cubic root of 20689837 is about 274.5273954275.

The spelling of 20689837 in words is "twenty million, six hundred eighty-nine thousand, eight hundred thirty-seven".