20945651 has 2 divisors, whose sum is σ = 20945652. Its totient is φ = 20945650.

The previous prime is 20945623. The next prime is 20945693. The reversal of 20945651 is 15654902.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20945651 - 2¹⁴ = 20929267 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20945621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10472825 + 10472826.

It is an arithmetic number, because the mean of its divisors is an integer number (10472826).

Almost surely, 2^20945651 is an apocalyptic number.

20945651 is a deficient number, since it is larger than the sum of its proper divisors (1).

20945651 is an equidigital number, since it uses as much as digits as its factorization.

20945651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 20945651 is about 4576.6418911687. The cubic root of 20945651 is about 275.6542044459.

The spelling of 20945651 in words is "twenty million, nine hundred forty-five thousand, six hundred fifty-one".