20646415377541 has 2 divisors, whose sum is σ = 20646415377542. Its totient is φ = 20646415377540.

The previous prime is 20646415377481. The next prime is 20646415377559. The reversal of 20646415377541 is 14577351464602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17209878013441 + 3436537364100 = 4148479^2 + 1853790^2 .

It is a cyclic number.

It is not a de Polignac number, because 20646415377541 - 2¹⁵ = 20646415344773 is a prime.

It is a super-2 number, since 2×20646415377541² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20646415347541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10323207688770 + 10323207688771.

It is an arithmetic number, because the mean of its divisors is an integer number (10323207688771).

Almost surely, 2^{20646415377541} is an apocalyptic number.

It is an amenable number.

20646415377541 is a deficient number, since it is larger than the sum of its proper divisors (1).

20646415377541 is an equidigital number, since it uses as much as digits as its factorization.

20646415377541 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16934400, while the sum is 55.

The spelling of 20646415377541 in words is "twenty trillion, six hundred forty-six billion, four hundred fifteen million, three hundred seventy-seven thousand, five hundred forty-one".