21354797 has 2 divisors, whose sum is σ = 21354798. Its totient is φ = 21354796.

The previous prime is 21354721. The next prime is 21354799. The reversal of 21354797 is 79745312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21353641 + 1156 = 4621^2 + 34^2 .

It is a cyclic number.

It is not a de Polignac number, because 21354797 - 2¹² = 21350701 is a prime.

It is a super-2 number, since 2×21354797² = 912054709822418, which contains 22 as substring.

Together with 21354799, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21354797.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21354799) 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, 10677398 + 10677399.

It is an arithmetic number, because the mean of its divisors is an integer number (10677399).

Almost surely, 2^21354797 is an apocalyptic number.

It is an amenable number.

21354797 is a deficient number, since it is larger than the sum of its proper divisors (1).

21354797 is an equidigital number, since it uses as much as digits as its factorization.

21354797 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 52920, while the sum is 38.

The square root of 21354797 is about 4621.1250794585. The cubic root of 21354797 is about 277.4374915344.

The spelling of 21354797 in words is "twenty-one million, three hundred fifty-four thousand, seven hundred ninety-seven".