20147764657 has 2 divisors, whose sum is σ = 20147764658. Its totient is φ = 20147764656.

The previous prime is 20147764639. The next prime is 20147764667. The reversal of 20147764657 is 75646774102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18328827456 + 1818937201 = 135384^2 + 42649^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20147764657 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20147764657.

It is not a weakly prime, because it can be changed into another prime (20147764667) 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, 10073882328 + 10073882329.

It is an arithmetic number, because the mean of its divisors is an integer number (10073882329).

Almost surely, 2^20147764657 is an apocalyptic number.

It is an amenable number.

20147764657 is a deficient number, since it is larger than the sum of its proper divisors (1).

20147764657 is an equidigital number, since it uses as much as digits as its factorization.

20147764657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1975680, while the sum is 49.

The spelling of 20147764657 in words is "twenty billion, one hundred forty-seven million, seven hundred sixty-four thousand, six hundred fifty-seven".