20723537 has 2 divisors, whose sum is σ = 20723538. Its totient is φ = 20723536.

The previous prime is 20723519. The next prime is 20723539. The reversal of 20723537 is 73532702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12103441 + 8620096 = 3479^2 + 2936^2 .

It is a cyclic number.

It is not a de Polignac number, because 20723537 - 2⁶ = 20723473 is a prime.

Together with 20723539, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_1313597 and since 20723537 and 1313597 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20723539) 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 as a sum of consecutive naturals, namely, 10361768 + 10361769.

It is an arithmetic number, because the mean of its divisors is an integer number (10361769).

Almost surely, 2^20723537 is an apocalyptic number.

It is an amenable number.

20723537 is a deficient number, since it is larger than the sum of its proper divisors (1).

20723537 is an equidigital number, since it uses as much as digits as its factorization.

20723537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8820, while the sum is 29.

The square root of 20723537 is about 4552.3111712624. The cubic root of 20723537 is about 274.6763663888.

The spelling of 20723537 in words is "twenty million, seven hundred twenty-three thousand, five hundred thirty-seven".