20669949541 has 2 divisors, whose sum is σ = 20669949542. Its totient is φ = 20669949540.

The previous prime is 20669949529. The next prime is 20669949563. The reversal of 20669949541 is 14594996602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20433558916 + 236390625 = 142946^2 + 15375^2 .

It is a cyclic number.

It is not a de Polignac number, because 20669949541 - 2⁷ = 20669949413 is a prime.

It is a super-2 number, since 2×20669949541² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20669949581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10334974770 + 10334974771.

It is an arithmetic number, because the mean of its divisors is an integer number (10334974771).

Almost surely, 2^20669949541 is an apocalyptic number.

It is an amenable number.

20669949541 is a deficient number, since it is larger than the sum of its proper divisors (1).

20669949541 is an equidigital number, since it uses as much as digits as its factorization.

20669949541 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4199040, while the sum is 55.

The spelling of 20669949541 in words is "twenty billion, six hundred sixty-nine million, nine hundred forty-nine thousand, five hundred forty-one".