130724021 has 4 divisors (see below), whose sum is σ = 131753472. Its totient is φ = 129694572.

The previous prime is 130724017. The next prime is 130724053. The reversal of 130724021 is 120427031.

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: 120427031 = 17 ⋅7083943.

It is a cyclic number.

It is not a de Polignac number, because 130724021 - 2² = 130724017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 130723984 and 130724002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (130724081) 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, 514535 + ... + 514788.

It is an arithmetic number, because the mean of its divisors is an integer number (32938368).

Almost surely, 2^130724021 is an apocalyptic number.

It is an amenable number.

130724021 is a deficient number, since it is larger than the sum of its proper divisors (1029451).

130724021 is a wasteful number, since it uses less digits than its factorization.

130724021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1029450.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 130724021 is about 11433.4605872413. The cubic root of 130724021 is about 507.5184084177.

The spelling of 130724021 in words is "one hundred thirty million, seven hundred twenty-four thousand, twenty-one".