20656738 has 4 divisors (see below), whose sum is σ = 30985110. Its totient is φ = 10328368.

The previous prime is 20656733. The next prime is 20656763. The reversal of 20656738 is 83765602.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18688329 + 1968409 = 4323^2 + 1403^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20656697 and 20656706.

It is not an unprimeable number, because it can be changed into a prime (20656733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5164183 + ... + 5164186.

Almost surely, 2^20656738 is an apocalyptic number.

20656738 is a deficient number, since it is larger than the sum of its proper divisors (10328372).

20656738 is a wasteful number, since it uses less digits than its factorization.

20656738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10328371.

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 20656738 is about 4544.9684267330. The cubic root of 20656738 is about 274.3809236427.

The spelling of 20656738 in words is "twenty million, six hundred fifty-six thousand, seven hundred thirty-eight".