20666724 has 48 divisors (see below), whose sum is σ = 52364928. Its totient is φ = 6306048.

The previous prime is 20666689. The next prime is 20666743. The reversal of 20666724 is 42766602.

It is a super-2 number, since 2×20666724² = 854226961784352, which contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 20889 + ... + 21855.

It is an arithmetic number, because the mean of its divisors is an integer number (1090936).

Almost surely, 2^20666724 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 20666724, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26182464).

20666724 is an abundant number, since it is smaller than the sum of its proper divisors (31698204).

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

20666724 is a wasteful number, since it uses less digits than its factorization.

20666724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1124 (or 1122 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 33.

The square root of 20666724 is about 4546.0668714835. The cubic root of 20666724 is about 274.4251307920.

The spelling of 20666724 in words is "twenty million, six hundred sixty-six thousand, seven hundred twenty-four".