20291215344949 has 2 divisors, whose sum is σ = 20291215344950. Its totient is φ = 20291215344948.

The previous prime is 20291215344923. The next prime is 20291215344997. The reversal of 20291215344949 is 94944351219202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18025272201924 + 2265943143025 = 4245618^2 + 1505305^2 .

It is a cyclic number.

It is not a de Polignac number, because 20291215344949 - 2¹³ = 20291215336757 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20291215344949.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20291215644949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10145607672474 + 10145607672475.

It is an arithmetic number, because the mean of its divisors is an integer number (10145607672475).

Almost surely, 2^{20291215344949} is an apocalyptic number.

It is an amenable number.

20291215344949 is a deficient number, since it is larger than the sum of its proper divisors (1).

20291215344949 is an equidigital number, since it uses as much as digits as its factorization.

20291215344949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5598720, while the sum is 55.

The spelling of 20291215344949 in words is "twenty trillion, two hundred ninety-one billion, two hundred fifteen million, three hundred forty-four thousand, nine hundred forty-nine".