21736157 has 2 divisors, whose sum is σ = 21736158. Its totient is φ = 21736156.

The previous prime is 21736151. The next prime is 21736181. The reversal of 21736157 is 75163712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21724921 + 11236 = 4661^2 + 106^2 .

It is a cyclic number.

It is not a de Polignac number, because 21736157 - 2⁶ = 21736093 is a prime.

It is a super-2 number, since 2×21736157² = 944921042257298, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21736151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10868078 + 10868079.

It is an arithmetic number, because the mean of its divisors is an integer number (10868079).

Almost surely, 2^21736157 is an apocalyptic number.

It is an amenable number.

21736157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21736157 is an equidigital number, since it uses as much as digits as its factorization.

21736157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8820, while the sum is 32.

The square root of 21736157 is about 4662.2051649407. The cubic root of 21736157 is about 279.0792758711.

Adding to 21736157 its reverse (75163712), we get a palindrome (96899869).

The spelling of 21736157 in words is "twenty-one million, seven hundred thirty-six thousand, one hundred fifty-seven".