20478677 has 2 divisors, whose sum is σ = 20478678. Its totient is φ = 20478676.

The previous prime is 20478643. The next prime is 20478691. The reversal of 20478677 is 77687402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12103441 + 8375236 = 3479^2 + 2894^2 .

It is a cyclic number.

It is not a de Polignac number, because 20478677 - 2⁶ = 20478613 is a prime.

It is a Chen prime.

It is equal to p_1298993 and since 20478677 and 1298993 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20478607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10239338 + 10239339.

It is an arithmetic number, because the mean of its divisors is an integer number (10239339).

Almost surely, 2^20478677 is an apocalyptic number.

It is an amenable number.

20478677 is a deficient number, since it is larger than the sum of its proper divisors (1).

20478677 is an equidigital number, since it uses as much as digits as its factorization.

20478677 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 131712, while the sum is 41.

The square root of 20478677 is about 4525.3372250032. The cubic root of 20478677 is about 273.5902599399.

The spelling of 20478677 in words is "twenty million, four hundred seventy-eight thousand, six hundred seventy-seven".