1242043251 has 4 divisors (see below), whose sum is σ = 1656057672. Its totient is φ = 828028832.

The previous prime is 1242043247. The next prime is 1242043321. The reversal of 1242043251 is 1523402421.

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 1242043251 - 2² = 1242043247 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1242043051) 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, 207007206 + ... + 207007211.

It is an arithmetic number, because the mean of its divisors is an integer number (414014418).

Almost surely, 2^1242043251 is an apocalyptic number.

1242043251 is a deficient number, since it is larger than the sum of its proper divisors (414014421).

1242043251 is an equidigital number, since it uses as much as digits as its factorization.

1242043251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414014420.

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 1242043251 is about 35242.6339963403. The cubic root of 1242043251 is about 1074.9268386482.

Adding to 1242043251 its reverse (1523402421), we get a palindrome (2765445672).

The spelling of 1242043251 in words is "one billion, two hundred forty-two million, forty-three thousand, two hundred fifty-one".