21100727 has 2 divisors, whose sum is σ = 21100728. Its totient is φ = 21100726.

The previous prime is 21100711. The next prime is 21100733. The reversal of 21100727 is 72700112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21100727 - 2⁴ = 21100711 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21100699 and 21100708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21100787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550363 + 10550364.

It is an arithmetic number, because the mean of its divisors is an integer number (10550364).

Almost surely, 2^21100727 is an apocalyptic number.

21100727 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100727 is an equidigital number, since it uses as much as digits as its factorization.

21100727 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 21100727 is about 4593.5527644733. The cubic root of 21100727 is about 276.3328224328.

Adding to 21100727 its reverse (72700112), we get a palindrome (93800839).

The spelling of 21100727 in words is "twenty-one million, one hundred thousand, seven hundred twenty-seven".