20340212509 has 2 divisors, whose sum is σ = 20340212510. Its totient is φ = 20340212508.

The previous prime is 20340212461. The next prime is 20340212521. The reversal of 20340212509 is 90521204302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14968788409 + 5371424100 = 122347^2 + 73290^2 .

It is a cyclic number.

It is not a de Polignac number, because 20340212509 - 2¹¹ = 20340210461 is a prime.

It is a super-2 number, since 2×20340212509² (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 (20340212549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10170106254 + 10170106255.

It is an arithmetic number, because the mean of its divisors is an integer number (10170106255).

Almost surely, 2^20340212509 is an apocalyptic number.

It is an amenable number.

20340212509 is a deficient number, since it is larger than the sum of its proper divisors (1).

20340212509 is an equidigital number, since it uses as much as digits as its factorization.

20340212509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 28.

The spelling of 20340212509 in words is "twenty billion, three hundred forty million, two hundred twelve thousand, five hundred nine".