102217561961 has 4 divisors (see below), whose sum is σ = 102218578500. Its totient is φ = 102216545424.

The previous prime is 102217561867. The next prime is 102217561973. The reversal of 102217561961 is 169165712201.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 169165712201 = 1129 ⋅149836769.

It can be written as a sum of positive squares in 2 ways, for example, as 67265016025 + 34952545936 = 259355^2 + 186956^2 .

It is a cyclic number.

It is not a de Polignac number, because 102217561961 - 2²² = 102213367657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (102217561661) 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, 338546 + ... + 564843.

It is an arithmetic number, because the mean of its divisors is an integer number (25554644625).

Almost surely, 2^102217561961 is an apocalyptic number.

It is an amenable number.

102217561961 is a deficient number, since it is larger than the sum of its proper divisors (1016539).

102217561961 is an equidigital number, since it uses as much as digits as its factorization.

102217561961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1016538.

The product of its (nonzero) digits is 45360, while the sum is 41.

The spelling of 102217561961 in words is "one hundred two billion, two hundred seventeen million, five hundred sixty-one thousand, nine hundred sixty-one".