1264817038721 has 2 divisors, whose sum is σ = 1264817038722. Its totient is φ = 1264817038720.

The previous prime is 1264817038717. The next prime is 1264817038759. The reversal of 1264817038721 is 1278307184621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1128555652225 + 136261386496 = 1062335^2 + 369136^2 .

It is an emirp because it is prime and its reverse (1278307184621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1264817038721 - 2² = 1264817038717 is a prime.

It is a super-2 number, since 2×1264817038721² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1264817038721.

It is not a weakly prime, because it can be changed into another prime (1264817038711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632408519360 + 632408519361.

It is an arithmetic number, because the mean of its divisors is an integer number (632408519361).

Almost surely, 2^{1264817038721} is an apocalyptic number.

It is an amenable number.

1264817038721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1264817038721 is an equidigital number, since it uses as much as digits as its factorization.

1264817038721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 903168, while the sum is 50.

The spelling of 1264817038721 in words is "one trillion, two hundred sixty-four billion, eight hundred seventeen million, thirty-eight thousand, seven hundred twenty-one".