102019661 has 2 divisors, whose sum is σ = 102019662. Its totient is φ = 102019660.

The previous prime is 102019609. The next prime is 102019679. The reversal of 102019661 is 166910201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 97397161 + 4622500 = 9869^2 + 2150^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-102019661 is a prime.

It is a super-2 number, since 2×102019661² = 20816022461109842, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 102019661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102019681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51009830 + 51009831.

It is an arithmetic number, because the mean of its divisors is an integer number (51009831).

Almost surely, 2^102019661 is an apocalyptic number.

It is an amenable number.

102019661 is a deficient number, since it is larger than the sum of its proper divisors (1).

102019661 is an equidigital number, since it uses as much as digits as its factorization.

102019661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 102019661 is about 10100.4782560035. The cubic root of 102019661 is about 467.2628913824.

Adding to 102019661 its reverse (166910201), we get a palindrome (268929862).

The spelling of 102019661 in words is "one hundred two million, nineteen thousand, six hundred sixty-one".