339561520021 has 2 divisors, whose sum is σ = 339561520022. Its totient is φ = 339561520020.

The previous prime is 339561519971. The next prime is 339561520043. The reversal of 339561520021 is 120025165933.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 202580107921 + 136981412100 = 450089^2 + 370110^2 .

It is a cyclic number.

It is not a de Polignac number, because 339561520021 - 2⁷ = 339561519893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (339561520121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 169780760010 + 169780760011.

It is an arithmetic number, because the mean of its divisors is an integer number (169780760011).

Almost surely, 2^339561520021 is an apocalyptic number.

It is an amenable number.

339561520021 is a deficient number, since it is larger than the sum of its proper divisors (1).

339561520021 is an equidigital number, since it uses as much as digits as its factorization.

339561520021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48600, while the sum is 37.

Adding to 339561520021 its reverse (120025165933), we get a palindrome (459586685954).

The spelling of 339561520021 in words is "three hundred thirty-nine billion, five hundred sixty-one million, five hundred twenty thousand, twenty-one".