130240021 has 4 divisors (see below), whose sum is σ = 134441344. Its totient is φ = 126038700.

The previous prime is 130239983. The next prime is 130240039. The reversal of 130240021 is 120042031.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120042031 = 683 ⋅175757.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-130240021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 130239983 and 130240010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (130240051) 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, 2100615 + ... + 2100676.

It is an arithmetic number, because the mean of its divisors is an integer number (33610336).

Almost surely, 2^130240021 is an apocalyptic number.

It is an amenable number.

130240021 is a deficient number, since it is larger than the sum of its proper divisors (4201323).

130240021 is an equidigital number, since it uses as much as digits as its factorization.

130240021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4201322.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 130240021 is about 11412.2750142117. The cubic root of 130240021 is about 506.8912788646.

Adding to 130240021 its reverse (120042031), we get a palindrome (250282052).

The spelling of 130240021 in words is "one hundred thirty million, two hundred forty thousand, twenty-one".