130956821 has 4 divisors (see below), whose sum is σ = 131370252. Its totient is φ = 130543392.

The previous prime is 130956811. The next prime is 130956853. The reversal of 130956821 is 128659031.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 128659031 = 3881 ⋅33151.

It can be written as a sum of positive squares in 2 ways, for example, as 57168721 + 73788100 = 7561^2 + 8590^2 .

It is a cyclic number.

It is not a de Polignac number, because 130956821 - 2¹⁴ = 130940437 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 (130956811) 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, 206240 + ... + 206873.

It is an arithmetic number, because the mean of its divisors is an integer number (32842563).

Almost surely, 2^130956821 is an apocalyptic number.

It is an amenable number.

130956821 is a deficient number, since it is larger than the sum of its proper divisors (413431).

130956821 is an equidigital number, since it uses as much as digits as its factorization.

130956821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413430.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 130956821 is about 11443.6367034261. The cubic root of 130956821 is about 507.8195013050.

The spelling of 130956821 in words is "one hundred thirty million, nine hundred fifty-six thousand, eight hundred twenty-one".