4251221111 has 4 divisors (see below), whose sum is σ = 4341672672. Its totient is φ = 4160769552.

The previous prime is 4251221083. The next prime is 4251221119. The reversal of 4251221111 is 1111221524.

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 4251221111 - 2⁶ = 4251221047 is a prime.

It is a super-2 number, since 2×4251221111² = 36145761869224148642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4251221119) 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, 45225710 + ... + 45225803.

It is an arithmetic number, because the mean of its divisors is an integer number (1085418168).

Almost surely, 2^4251221111 is an apocalyptic number.

4251221111 is a deficient number, since it is larger than the sum of its proper divisors (90451561).

4251221111 is an equidigital number, since it uses as much as digits as its factorization.

4251221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90451560.

The product of its digits is 160, while the sum is 20.

The square root of 4251221111 is about 65201.3888732441. The cubic root of 4251221111 is about 1619.9610201209.

Adding to 4251221111 its reverse (1111221524), we get a palindrome (5362442635).

The spelling of 4251221111 in words is "four billion, two hundred fifty-one million, two hundred twenty-one thousand, one hundred eleven".