20416153265561 has 2 divisors, whose sum is σ = 20416153265562. Its totient is φ = 20416153265560.

The previous prime is 20416153265549. The next prime is 20416153265587. The reversal of 20416153265561 is 16556235161402.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13248646337161 + 7167506928400 = 3639869^2 + 2677220^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20416153265561 is a prime.

It is not a weakly prime, because it can be changed into another prime (20416153261561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10208076632780 + 10208076632781.

It is an arithmetic number, because the mean of its divisors is an integer number (10208076632781).

Almost surely, 2^{20416153265561} is an apocalyptic number.

It is an amenable number.

20416153265561 is a deficient number, since it is larger than the sum of its proper divisors (1).

20416153265561 is an equidigital number, since it uses as much as digits as its factorization.

20416153265561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296000, while the sum is 47.

The spelling of 20416153265561 in words is "twenty trillion, four hundred sixteen billion, one hundred fifty-three million, two hundred sixty-five thousand, five hundred sixty-one".