102618721 has 2 divisors, whose sum is σ = 102618722. Its totient is φ = 102618720.

The previous prime is 102618697. The next prime is 102618739. The reversal of 102618721 is 127816201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74909025 + 27709696 = 8655^2 + 5264^2 .

It is a cyclic number.

It is not a de Polignac number, because 102618721 - 2⁹ = 102618209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 102618721.

It is not a weakly prime, because it can be changed into another prime (102618751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51309360 + 51309361.

It is an arithmetic number, because the mean of its divisors is an integer number (51309361).

Almost surely, 2^102618721 is an apocalyptic number.

It is an amenable number.

102618721 is a deficient number, since it is larger than the sum of its proper divisors (1).

102618721 is an equidigital number, since it uses as much as digits as its factorization.

102618721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 102618721 is about 10130.0898811412. The cubic root of 102618721 is about 468.1756971136.

The spelling of 102618721 in words is "one hundred two million, six hundred eighteen thousand, seven hundred twenty-one".