20613457 has 2 divisors, whose sum is σ = 20613458. Its totient is φ = 20613456.

The previous prime is 20613433. The next prime is 20613473. The reversal of 20613457 is 75431602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13220496 + 7392961 = 3636^2 + 2719^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20613457 is a prime.

It is not a weakly prime, because it can be changed into another prime (20613407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10306728 + 10306729.

It is an arithmetic number, because the mean of its divisors is an integer number (10306729).

Almost surely, 2^20613457 is an apocalyptic number.

It is an amenable number.

20613457 is a deficient number, since it is larger than the sum of its proper divisors (1).

20613457 is an equidigital number, since it uses as much as digits as its factorization.

20613457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 20613457 is about 4540.2045108123. The cubic root of 20613457 is about 274.1891575718.

The spelling of 20613457 in words is "twenty million, six hundred thirteen thousand, four hundred fifty-seven".