21111248279497 has 2 divisors, whose sum is σ = 21111248279498. Its totient is φ = 21111248279496.

The previous prime is 21111248279483. The next prime is 21111248279551. The reversal of 21111248279497 is 79497284211112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12599582068921 + 8511666210576 = 3549589^2 + 2917476^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111248279497 is a prime.

It is not a weakly prime, because it can be changed into another prime (21111248279417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555624139748 + 10555624139749.

It is an arithmetic number, because the mean of its divisors is an integer number (10555624139749).

Almost surely, 2^{21111248279497} is an apocalyptic number.

It is an amenable number.

21111248279497 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111248279497 is an equidigital number, since it uses as much as digits as its factorization.

21111248279497 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4064256, while the sum is 58.

The spelling of 21111248279497 in words is "twenty-one trillion, one hundred eleven billion, two hundred forty-eight million, two hundred seventy-nine thousand, four hundred ninety-seven".