2151530021 has 8 divisors (see below), whose sum is σ = 2159930784. Its totient is φ = 2143144080.

The previous prime is 2151530011. The next prime is 2151530089. The reversal of 2151530021 is 1200351512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2151530021 - 2⁶ = 2151529957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2151529975 and 2151530002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2151530011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 350186 + ... + 356276.

It is an arithmetic number, because the mean of its divisors is an integer number (269991348).

Almost surely, 2^2151530021 is an apocalyptic number.

It is an amenable number.

2151530021 is a deficient number, since it is larger than the sum of its proper divisors (8400763).

2151530021 is an equidigital number, since it uses as much as digits as its factorization.

2151530021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7411.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 2151530021 is about 46384.5881840078. The cubic root of 2151530021 is about 1290.9689695210.

Adding to 2151530021 its reverse (1200351512), we get a palindrome (3351881533).

The spelling of 2151530021 in words is "two billion, one hundred fifty-one million, five hundred thirty thousand, twenty-one".