1242257251 has 16 divisors (see below), whose sum is σ = 1290428928. Its totient is φ = 1195286400.

The previous prime is 1242257207. The next prime is 1242257309. The reversal of 1242257251 is 1527522421.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1242257251 - 2⁷ = 1242257123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1242257851) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 536386 + ... + 538696.

It is an arithmetic number, because the mean of its divisors is an integer number (80651808).

Almost surely, 2^1242257251 is an apocalyptic number.

1242257251 is a deficient number, since it is larger than the sum of its proper divisors (48171677).

1242257251 is a wasteful number, since it uses less digits than its factorization.

1242257251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2562.

The product of its digits is 11200, while the sum is 31.

The square root of 1242257251 is about 35245.6699610037. The cubic root of 1242257251 is about 1074.9885705653.

Adding to 1242257251 its reverse (1527522421), we get a palindrome (2769779672).

The spelling of 1242257251 in words is "one billion, two hundred forty-two million, two hundred fifty-seven thousand, two hundred fifty-one".