1242401551 has 2 divisors, whose sum is σ = 1242401552. Its totient is φ = 1242401550.

The previous prime is 1242401543. The next prime is 1242401581. The reversal of 1242401551 is 1551042421.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1242401551 - 2³ = 1242401543 is a prime.

It is a super-2 number, since 2×1242401551² = 3087123227854411202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1242401521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621200775 + 621200776.

It is an arithmetic number, because the mean of its divisors is an integer number (621200776).

Almost surely, 2^1242401551 is an apocalyptic number.

1242401551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1242401551 is an equidigital number, since it uses as much as digits as its factorization.

1242401551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1600, while the sum is 25.

The square root of 1242401551 is about 35247.7169615282. The cubic root of 1242401551 is about 1075.0301923375.

Adding to 1242401551 its reverse (1551042421), we get a palindrome (2793443972).

The spelling of 1242401551 in words is "one billion, two hundred forty-two million, four hundred one thousand, five hundred fifty-one".