102138647 has 4 divisors (see below), whose sum is σ = 109995480. Its totient is φ = 94281816.

The previous prime is 102138643. The next prime is 102138649. The reversal of 102138647 is 746831201.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 746831201 = 191 ⋅3910111.

It is a cyclic number.

It is not a de Polignac number, because 102138647 - 2² = 102138643 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102138643) 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, 3928397 + ... + 3928422.

It is an arithmetic number, because the mean of its divisors is an integer number (27498870).

Almost surely, 2^102138647 is an apocalyptic number.

102138647 is a deficient number, since it is larger than the sum of its proper divisors (7856833).

102138647 is an equidigital number, since it uses as much as digits as its factorization.

102138647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7856832.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 102138647 is about 10106.3666567169. The cubic root of 102138647 is about 467.4444777590. Note that the first 4 decimals are identical.

Adding to 102138647 its reverse (746831201), we get a palindrome (848969848).

The spelling of 102138647 in words is "one hundred two million, one hundred thirty-eight thousand, six hundred forty-seven".