102123657761 has 4 divisors (see below), whose sum is σ = 104614478724. Its totient is φ = 99632836800.

The previous prime is 102123657737. The next prime is 102123657773. The reversal of 102123657761 is 167756321201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 167756321201 = 7 ⋅23965188743.

It can be written as a sum of positive squares in 2 ways, for example, as 45643758736 + 56479899025 = 213644^2 + 237655^2 .

It is a cyclic number.

It is not a de Polignac number, because 102123657761 - 2¹⁰ = 102123656737 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 2490820921 = 102123657761 / (1 + 0 + 2 + 1 + 2 + 3 + 6 + 5 + 7 + 7 + 6 + 1).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (102123654761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1245410420 + ... + 1245410501.

It is an arithmetic number, because the mean of its divisors is an integer number (26153619681).

Almost surely, 2^102123657761 is an apocalyptic number.

It is an amenable number.

102123657761 is a deficient number, since it is larger than the sum of its proper divisors (2490820963).

102123657761 is an equidigital number, since it uses as much as digits as its factorization.

102123657761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2490820962.

The product of its (nonzero) digits is 105840, while the sum is 41.

Adding to 102123657761 its reverse (167756321201), we get a palindrome (269879978962).

The spelling of 102123657761 in words is "one hundred two billion, one hundred twenty-three million, six hundred fifty-seven thousand, seven hundred sixty-one".