20689632 has 108 divisors (see below), whose sum is σ = 62407800. Its totient is φ = 6500736.

The previous prime is 20689621. The next prime is 20689633. The reversal of 20689632 is 23698602.

It is a super-4 number, since 4×20689632⁴ (a number of 30 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20689633) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 103869 + ... + 104067.

It is an arithmetic number, because the mean of its divisors is an integer number (577850).

Almost surely, 2^20689632 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 20689632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31203900).

20689632 is an abundant number, since it is smaller than the sum of its proper divisors (41718168).

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

20689632 is a wasteful number, since it uses less digits than its factorization.

20689632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253 (or 223 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 20689632 is about 4548.5857142633. The cubic root of 20689632 is about 274.5264887295.

It can be divided in two parts, 20689 and 632, that added together give a triangular number (21321 = T₂₀₆).

The spelling of 20689632 in words is "twenty million, six hundred eighty-nine thousand, six hundred thirty-two".