21334201997 has 2 divisors, whose sum is σ = 21334201998. Its totient is φ = 21334201996.

The previous prime is 21334201981. The next prime is 21334202011. The reversal of 21334201997 is 79910243312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17811304681 + 3522897316 = 133459^2 + 59354^2 .

It is a cyclic number.

It is not a de Polignac number, because 21334201997 - 2⁴ = 21334201981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21334201957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10667100998 + 10667100999.

It is an arithmetic number, because the mean of its divisors is an integer number (10667100999).

Almost surely, 2^21334201997 is an apocalyptic number.

It is an amenable number.

21334201997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21334201997 is an equidigital number, since it uses as much as digits as its factorization.

21334201997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81648, while the sum is 41.

The spelling of 21334201997 in words is "twenty-one billion, three hundred thirty-four million, two hundred one thousand, nine hundred ninety-seven".