20878577 has 2 divisors, whose sum is σ = 20878578. Its totient is φ = 20878576.

The previous prime is 20878541. The next prime is 20878591. The reversal of 20878577 is 77587802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19280881 + 1597696 = 4391^2 + 1264^2 .

It is a cyclic number.

It is not a de Polignac number, because 20878577 - 2⁶ = 20878513 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20878537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10439288 + 10439289.

It is an arithmetic number, because the mean of its divisors is an integer number (10439289).

Almost surely, 2^20878577 is an apocalyptic number.

It is an amenable number.

20878577 is a deficient number, since it is larger than the sum of its proper divisors (1).

20878577 is an equidigital number, since it uses as much as digits as its factorization.

20878577 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 219520, while the sum is 44.

The square root of 20878577 is about 4569.3081533204. The cubic root of 20878577 is about 275.3596484505.

The spelling of 20878577 in words is "twenty million, eight hundred seventy-eight thousand, five hundred seventy-seven".