1242331781 has 4 divisors (see below), whose sum is σ = 1242404064. Its totient is φ = 1242259500.

The previous prime is 1242331771. The next prime is 1242331787. The reversal of 1242331781 is 1871332421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1242331781 - 2¹⁰ = 1242330757 is a prime.

It is a super-2 number, since 2×1242331781² = 3086776508165263922, 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 (1242331787) 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, 6086 + ... + 50216.

It is an arithmetic number, because the mean of its divisors is an integer number (310601016).

Almost surely, 2^1242331781 is an apocalyptic number.

It is an amenable number.

1242331781 is a deficient number, since it is larger than the sum of its proper divisors (72283).

1242331781 is an equidigital number, since it uses as much as digits as its factorization.

1242331781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72282.

The product of its digits is 8064, while the sum is 32.

The square root of 1242331781 is about 35246.7272381423. The cubic root of 1242331781 is about 1075.0100683391.

The spelling of 1242331781 in words is "one billion, two hundred forty-two million, three hundred thirty-one thousand, seven hundred eighty-one".