102402421 has 24 divisors (see below), whose sum is σ = 117353880. Its totient is φ = 89210880.

The previous prime is 102402397. The next prime is 102402427. The reversal of 102402421 is 124204201.

It can be written as a sum of positive squares in 4 ways, for example, as 51122500 + 51279921 = 7150^2 + 7161^2 .

It is not a de Polignac number, because 102402421 - 2⁹ = 102401909 is a prime.

It is a super-2 number, since 2×102402421² = 20972511653322482, 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 = 102402395 and 102402404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102402427) 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 23 ways as a sum of consecutive naturals, for example, 398325 + ... + 398581.

It is an arithmetic number, because the mean of its divisors is an integer number (4889745).

Almost surely, 2^102402421 is an apocalyptic number.

102402421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

102402421 is a deficient number, since it is larger than the sum of its proper divisors (14951459).

102402421 is a wasteful number, since it uses less digits than its factorization.

102402421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405 (or 394 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 102402421 is about 10119.4081348664. The cubic root of 102402421 is about 467.8465250886.

Adding to 102402421 its reverse (124204201), we get a palindrome (226606622).

The spelling of 102402421 in words is "one hundred two million, four hundred two thousand, four hundred twenty-one".