102120345521 has 4 divisors (see below), whose sum is σ = 102129464052. Its totient is φ = 102111226992.

The previous prime is 102120345511. The next prime is 102120345527. The reversal of 102120345521 is 125543021201.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35357537296 + 66762808225 = 188036^2 + 258385^2 .

It is a cyclic number.

It is not a de Polignac number, because 102120345521 - 2²² = 102116151217 is a prime.

It is a super-2 number, since 2×102120345521² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (102120345527) 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, 4542446 + ... + 4564871.

It is an arithmetic number, because the mean of its divisors is an integer number (25532366013).

Almost surely, 2^102120345521 is an apocalyptic number.

It is an amenable number.

102120345521 is a deficient number, since it is larger than the sum of its proper divisors (9118531).

102120345521 is an equidigital number, since it uses as much as digits as its factorization.

102120345521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9118530.

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 102120345521 its reverse (125543021201), we get a palindrome (227663366722).

The spelling of 102120345521 in words is "one hundred two billion, one hundred twenty million, three hundred forty-five thousand, five hundred twenty-one".