20712644 has 6 divisors (see below), whose sum is σ = 36247134. Its totient is φ = 10356320.

The previous prime is 20712631. The next prime is 20712649. The reversal of 20712644 is 44621702.

It can be written as a sum of positive squares in only one way, i.e., 17056900 + 3655744 = 4130^2 + 1912^2 .

It is a super-3 number, since 3×20712644³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (20712649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2589077 + ... + 2589084.

It is an arithmetic number, because the mean of its divisors is an integer number (6041189).

Almost surely, 2^20712644 is an apocalyptic number.

It is an amenable number.

20712644 is a deficient number, since it is larger than the sum of its proper divisors (15534490).

20712644 is a wasteful number, since it uses less digits than its factorization.

20712644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5178165 (or 5178163 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 20712644 is about 4551.1145887574. The cubic root of 20712644 is about 274.6282315224.

The spelling of 20712644 in words is "twenty million, seven hundred twelve thousand, six hundred forty-four".