102731561 has 8 divisors (see below), whose sum is σ = 109324800. Its totient is φ = 96199488.

The previous prime is 102731557. The next prime is 102731579. The reversal of 102731561 is 165137201.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 102731561 - 2² = 102731557 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 102731561.

It is not an unprimeable number, because it can be changed into a prime (102731261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11801 + ... + 18566.

It is an arithmetic number, because the mean of its divisors is an integer number (13665600).

Almost surely, 2^102731561 is an apocalyptic number.

It is an amenable number.

102731561 is a deficient number, since it is larger than the sum of its proper divisors (6593239).

102731561 is a wasteful number, since it uses less digits than its factorization.

102731561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30583.

The product of its (nonzero) digits is 1260, while the sum is 26.

The square root of 102731561 is about 10135.6578967524. The cubic root of 102731561 is about 468.3472369435.

Adding to 102731561 its reverse (165137201), we get a palindrome (267868762).

The spelling of 102731561 in words is "one hundred two million, seven hundred thirty-one thousand, five hundred sixty-one".