102199981 has 16 divisors (see below), whose sum is σ = 111949488. Its totient is φ = 92736000.

The previous prime is 102199969. The next prime is 102199987. The reversal of 102199981 is 189991201.

It can be written as a sum of positive squares in 8 ways, for example, as 8100 + 102191881 = 90^2 + 10109^2 .

It is a cyclic number.

It is not a de Polignac number, because 102199981 - 2¹¹ = 102197933 is a prime.

It is a super-2 number, since 2×102199981² = 20889672232800722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102199987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 363561 + ... + 363841.

It is an arithmetic number, because the mean of its divisors is an integer number (6996843).

Almost surely, 2^102199981 is an apocalyptic number.

It is an amenable number.

102199981 is a deficient number, since it is larger than the sum of its proper divisors (9749507).

102199981 is a wasteful number, since it uses less digits than its factorization.

102199981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 102199981 is about 10109.4006251607. The cubic root of 102199981 is about 467.5380254466.

The spelling of 102199981 in words is "one hundred two million, one hundred ninety-nine thousand, nine hundred eighty-one".