20691744 has 48 divisors (see below), whose sum is σ = 55143648. Its totient is φ = 6792192.

The previous prime is 20691733. The next prime is 20691791. The reversal of 20691744 is 44719602.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4824 + ... + 8040.

It is an arithmetic number, because the mean of its divisors is an integer number (1148826).

Almost surely, 2^20691744 is an apocalyptic number.

20691744 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20691744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27571824).

20691744 is an abundant number, since it is smaller than the sum of its proper divisors (34451904).

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

20691744 is a wasteful number, since it uses less digits than its factorization.

20691744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3297 (or 3289 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 20691744 is about 4548.8178684137. The cubic root of 20691744 is about 274.5358296435.

The spelling of 20691744 in words is "twenty million, six hundred ninety-one thousand, seven hundred forty-four".