2151222251 has 4 divisors (see below), whose sum is σ = 2152049400. Its totient is φ = 2150395104.

The previous prime is 2151222239. The next prime is 2151222287. The reversal of 2151222251 is 1522221512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2151222251 - 2¹⁰ = 2151221227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2151222221) 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, 409661 + ... + 414878.

It is an arithmetic number, because the mean of its divisors is an integer number (538012350).

Almost surely, 2^2151222251 is an apocalyptic number.

2151222251 is a deficient number, since it is larger than the sum of its proper divisors (827149).

2151222251 is an equidigital number, since it uses as much as digits as its factorization.

2151222251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 827148.

The product of its digits is 800, while the sum is 23.

The square root of 2151222251 is about 46381.2704763464. The cubic root of 2151222251 is about 1290.9074101559.

Adding to 2151222251 its reverse (1522221512), we get a palindrome (3673443763).

The spelling of 2151222251 in words is "two billion, one hundred fifty-one million, two hundred twenty-two thousand, two hundred fifty-one".