21003333397 has 2 divisors, whose sum is σ = 21003333398. Its totient is φ = 21003333396.

The previous prime is 21003333389. The next prime is 21003333409. The reversal of 21003333397 is 79333330012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19969646596 + 1033686801 = 141314^2 + 32151^2 .

It is a cyclic number.

It is not a de Polignac number, because 21003333397 - 2³ = 21003333389 is a prime.

It is a super-2 number, since 2×21003333397² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21003333367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501666698 + 10501666699.

It is an arithmetic number, because the mean of its divisors is an integer number (10501666699).

Almost surely, 2^21003333397 is an apocalyptic number.

It is an amenable number.

21003333397 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003333397 is an equidigital number, since it uses as much as digits as its factorization.

21003333397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30618, while the sum is 34.

The spelling of 21003333397 in words is "twenty-one billion, three million, three hundred thirty-three thousand, three hundred ninety-seven".