20591616 has 44 divisors (see below), whose sum is σ = 54892352. Its totient is φ = 6862848.

The previous prime is 20591609. The next prime is 20591617. The reversal of 20591616 is 61619502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20591617) 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, 280 + ... + 6423.

Almost surely, 2^20591616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20591616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27446176).

20591616 is an abundant number, since it is smaller than the sum of its proper divisors (34300736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20591616 is an equidigital number, since it uses as much as digits as its factorization.

20591616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6726 (or 6708 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 20591616 is about 4537.7985852173. The cubic root of 20591616 is about 274.0922842575.

The spelling of 20591616 in words is "twenty million, five hundred ninety-one thousand, six hundred sixteen".