130557821 has 4 divisors (see below), whose sum is σ = 136234272. Its totient is φ = 124881372.

The previous prime is 130557781. The next prime is 130557839. The reversal of 130557821 is 128755031.

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: 128755031 = 7691 ⋅16741.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-130557821 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (130557871) 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, 2838191 + ... + 2838236.

It is an arithmetic number, because the mean of its divisors is an integer number (34058568).

Almost surely, 2^130557821 is an apocalyptic number.

It is an amenable number.

130557821 is a deficient number, since it is larger than the sum of its proper divisors (5676451).

130557821 is an equidigital number, since it uses as much as digits as its factorization.

130557821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5676450.

The product of its (nonzero) digits is 8400, while the sum is 32.

The square root of 130557821 is about 11426.1901349487. The cubic root of 130557821 is about 507.3032341625.

The spelling of 130557821 in words is "one hundred thirty million, five hundred fifty-seven thousand, eight hundred twenty-one".