64188749 has 2 divisors, whose sum is σ = 64188750. Its totient is φ = 64188748.

The previous prime is 64188713. The next prime is 64188769. The reversal of 64188749 is 94788146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59013124 + 5175625 = 7682^2 + 2275^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64188749 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64188769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32094374 + 32094375.

It is an arithmetic number, because the mean of its divisors is an integer number (32094375).

Almost surely, 2^64188749 is an apocalyptic number.

It is an amenable number.

64188749 is a deficient number, since it is larger than the sum of its proper divisors (1).

64188749 is an equidigital number, since it uses as much as digits as its factorization.

64188749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 387072, while the sum is 47.

The square root of 64188749 is about 8011.7881275031. The cubic root of 64188749 is about 400.3928411466.

The spelling of 64188749 in words is "sixty-four million, one hundred eighty-eight thousand, seven hundred forty-nine".