20723536 has 10 divisors (see below), whose sum is σ = 40151882. Its totient is φ = 10361760.

The previous prime is 20723519. The next prime is 20723537. The reversal of 20723536 is 63532702.

It can be written as a sum of positive squares in only one way, i.e., 17640000 + 3083536 = 4200^2 + 1756^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20723537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 647595 + ... + 647626.

Almost surely, 2^20723536 is an apocalyptic number.

It is an amenable number.

20723536 is a deficient number, since it is larger than the sum of its proper divisors (19428346).

20723536 is a wasteful number, since it uses less digits than its factorization.

20723536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1295229 (or 1295223 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 28.

The square root of 20723536 is about 4552.3110614280. The cubic root of 20723536 is about 274.6763619707.

The spelling of 20723536 in words is "twenty million, seven hundred twenty-three thousand, five hundred thirty-six".