2151621317 has 4 divisors (see below), whose sum is σ = 2183735136. Its totient is φ = 2119507500.

The previous prime is 2151621293. The next prime is 2151621323. The reversal of 2151621317 is 7131261512.

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.

It is a cyclic number.

It is not a de Polignac number, because 2151621317 - 2³⁰ = 1077879493 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2151621317.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2151621347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16056809 + ... + 16056942.

It is an arithmetic number, because the mean of its divisors is an integer number (545933784).

Almost surely, 2^2151621317 is an apocalyptic number.

It is an amenable number.

2151621317 is a deficient number, since it is larger than the sum of its proper divisors (32113819).

2151621317 is an equidigital number, since it uses as much as digits as its factorization.

2151621317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32113818.

The product of its digits is 2520, while the sum is 29.

The square root of 2151621317 is about 46385.5722935483. The cubic root of 2151621317 is about 1290.9872291835.

Adding to 2151621317 its reverse (7131261512), we get a palindrome (9282882829).

The spelling of 2151621317 in words is "two billion, one hundred fifty-one million, six hundred twenty-one thousand, three hundred seventeen".