20645251500413 has 2 divisors, whose sum is σ = 20645251500414. Its totient is φ = 20645251500412.

The previous prime is 20645251500383. The next prime is 20645251500473. The reversal of 20645251500413 is 31400515254602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10720470769369 + 9924780731044 = 3274213^2 + 3150362^2 .

It is a cyclic number.

It is not a de Polignac number, because 20645251500413 - 2³² = 20640956533117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20645251500473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322625750206 + 10322625750207.

It is an arithmetic number, because the mean of its divisors is an integer number (10322625750207).

Almost surely, 2^{20645251500413} is an apocalyptic number.

It is an amenable number.

20645251500413 is a deficient number, since it is larger than the sum of its proper divisors (1).

20645251500413 is an equidigital number, since it uses as much as digits as its factorization.

20645251500413 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144000, while the sum is 38.

The spelling of 20645251500413 in words is "twenty trillion, six hundred forty-five billion, two hundred fifty-one million, five hundred thousand, four hundred thirteen".