21041420497 has 2 divisors, whose sum is σ = 21041420498. Its totient is φ = 21041420496.

The previous prime is 21041420473. The next prime is 21041420513. The reversal of 21041420497 is 79402414012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19640340736 + 1401079761 = 140144^2 + 37431^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21041420497 is a prime.

It is not a weakly prime, because it can be changed into another prime (21041420297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10520710248 + 10520710249.

It is an arithmetic number, because the mean of its divisors is an integer number (10520710249).

Almost surely, 2^21041420497 is an apocalyptic number.

It is an amenable number.

21041420497 is a deficient number, since it is larger than the sum of its proper divisors (1).

21041420497 is an equidigital number, since it uses as much as digits as its factorization.

21041420497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 34.

The spelling of 21041420497 in words is "twenty-one billion, forty-one million, four hundred twenty thousand, four hundred ninety-seven".