20291648 has 56 divisors (see below), whose sum is σ = 44912280. Its totient is φ = 9042432.

The previous prime is 20291611. The next prime is 20291653. The reversal of 20291648 is 84619202.

It can be written as a sum of positive squares in 4 ways, for example, as 506944 + 19784704 = 712^2 + 4448^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 699698 + ... + 699726.

It is an arithmetic number, because the mean of its divisors is an integer number (802005).

Almost surely, 2^20291648 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 20291648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22456140).

20291648 is an abundant number, since it is smaller than the sum of its proper divisors (24620632).

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

20291648 is an frugal number, since it uses more digits than its factorization.

20291648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 20291648 is about 4504.6251786358. The cubic root of 20291648 is about 272.7548237756.

The spelling of 20291648 in words is "twenty million, two hundred ninety-one thousand, six hundred forty-eight".