102138431 has 4 divisors (see below), whose sum is σ = 108146592. Its totient is φ = 96130272.

The previous prime is 102138401. The next prime is 102138437. The reversal of 102138431 is 134831201.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-102138431 is a prime.

It is a super-2 number, since 2×102138431² = 20864518174283522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 102138397 and 102138406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102138437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3004055 + ... + 3004088.

It is an arithmetic number, because the mean of its divisors is an integer number (27036648).

Almost surely, 2^102138431 is an apocalyptic number.

102138431 is a deficient number, since it is larger than the sum of its proper divisors (6008161).

102138431 is an equidigital number, since it uses as much as digits as its factorization.

102138431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6008160.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 102138431 is about 10106.3559703782. The cubic root of 102138431 is about 467.4441482459. Note that the first 3 decimals are identical.

Adding to 102138431 its reverse (134831201), we get a palindrome (236969632).

The spelling of 102138431 in words is "one hundred two million, one hundred thirty-eight thousand, four hundred thirty-one".