21327751 has 2 divisors, whose sum is σ = 21327752. Its totient is φ = 21327750.

The previous prime is 21327727. The next prime is 21327781. The reversal of 21327751 is 15772312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21327751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21327701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10663875 + 10663876.

It is an arithmetic number, because the mean of its divisors is an integer number (10663876).

Almost surely, 2^21327751 is an apocalyptic number.

21327751 is a deficient number, since it is larger than the sum of its proper divisors (1).

21327751 is an equidigital number, since it uses as much as digits as its factorization.

21327751 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2940, while the sum is 28.

The square root of 21327751 is about 4618.1978086695. The cubic root of 21327751 is about 277.3203165439.

The spelling of 21327751 in words is "twenty-one million, three hundred twenty-seven thousand, seven hundred fifty-one".