21790006499 has 2 divisors, whose sum is σ = 21790006500. Its totient is φ = 21790006498.

The previous prime is 21790006489. The next prime is 21790006519. The reversal of 21790006499 is 99460009712.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21790006499 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21790006439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10895003249 + 10895003250.

It is an arithmetic number, because the mean of its divisors is an integer number (10895003250).

Almost surely, 2^21790006499 is an apocalyptic number.

21790006499 is a deficient number, since it is larger than the sum of its proper divisors (1).

21790006499 is an equidigital number, since it uses as much as digits as its factorization.

21790006499 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 244944, while the sum is 47.

The spelling of 21790006499 in words is "twenty-one billion, seven hundred ninety million, six thousand, four hundred ninety-nine".