20774639 has 2 divisors, whose sum is σ = 20774640. Its totient is φ = 20774638.

The previous prime is 20774627. The next prime is 20774653. The reversal of 20774639 is 93647702.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20774639 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20774609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10387319 + 10387320.

It is an arithmetic number, because the mean of its divisors is an integer number (10387320).

Almost surely, 2^20774639 is an apocalyptic number.

20774639 is a deficient number, since it is larger than the sum of its proper divisors (1).

20774639 is an equidigital number, since it uses as much as digits as its factorization.

20774639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63504, while the sum is 38.

The square root of 20774639 is about 4557.9204688103. The cubic root of 20774639 is about 274.9019551312.

The spelling of 20774639 in words is "twenty million, seven hundred seventy-four thousand, six hundred thirty-nine".