21792437 has 2 divisors, whose sum is σ = 21792438. Its totient is φ = 21792436.

The previous prime is 21792403. The next prime is 21792439. The reversal of 21792437 is 73429712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19439281 + 2353156 = 4409^2 + 1534^2 .

It is a cyclic number.

It is not a de Polignac number, because 21792437 - 2¹² = 21788341 is a prime.

Together with 21792439, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21792397 and 21792406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21792439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10896218 + 10896219.

It is an arithmetic number, because the mean of its divisors is an integer number (10896219).

Almost surely, 2^21792437 is an apocalyptic number.

It is an amenable number.

21792437 is a deficient number, since it is larger than the sum of its proper divisors (1).

21792437 is an equidigital number, since it uses as much as digits as its factorization.

21792437 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21168, while the sum is 35.

The square root of 21792437 is about 4668.2370333992. The cubic root of 21792437 is about 279.3199354796.

The spelling of 21792437 in words is "twenty-one million, seven hundred ninety-two thousand, four hundred thirty-seven".