20477917 has 2 divisors, whose sum is σ = 20477918. Its totient is φ = 20477916.

The previous prime is 20477903. The next prime is 20477923. The reversal of 20477917 is 71977402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10830681 + 9647236 = 3291^2 + 3106^2 .

It is a cyclic number.

It is not a de Polignac number, because 20477917 - 2¹⁵ = 20445149 is a prime.

It is equal to p_1298944 and since 20477917 and 1298944 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 (20477927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10238958 + 10238959.

It is an arithmetic number, because the mean of its divisors is an integer number (10238959).

Almost surely, 2^20477917 is an apocalyptic number.

It is an amenable number.

20477917 is a deficient number, since it is larger than the sum of its proper divisors (1).

20477917 is an equidigital number, since it uses as much as digits as its factorization.

20477917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24696, while the sum is 37.

The square root of 20477917 is about 4525.2532525816. The cubic root of 20477917 is about 273.5868754249.

The spelling of 20477917 in words is "twenty million, four hundred seventy-seven thousand, nine hundred seventeen".