1242221251 has 4 divisors (see below), whose sum is σ = 1244268352. Its totient is φ = 1240174152.

The previous prime is 1242221231. The next prime is 1242221291. The reversal of 1242221251 is 1521222421.

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 1242221251 - 2⁹ = 1242220739 is a prime.

It is a super-2 number, since 2×1242221251² = 3086227272872010002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1242221221) 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, 1022640 + ... + 1023853.

It is an arithmetic number, because the mean of its divisors is an integer number (311067088).

Almost surely, 2^1242221251 is an apocalyptic number.

1242221251 is a deficient number, since it is larger than the sum of its proper divisors (2047101).

1242221251 is an equidigital number, since it uses as much as digits as its factorization.

1242221251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2047100.

The product of its digits is 640, while the sum is 22.

The square root of 1242221251 is about 35245.1592562723. The cubic root of 1242221251 is about 1074.9781862529.

Adding to 1242221251 its reverse (1521222421), we get a palindrome (2763443672).

The spelling of 1242221251 in words is "one billion, two hundred forty-two million, two hundred twenty-one thousand, two hundred fifty-one".