1281136429 has 4 divisors (see below), whose sum is σ = 1282456800. Its totient is φ = 1279816060.

The previous prime is 1281136421. The next prime is 1281136447. The reversal of 1281136429 is 9246311821.

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 an emirpimes, since its reverse is a distinct semiprime: 9246311821 = 197 ⋅46935593.

It is a cyclic number.

It is not a de Polignac number, because 1281136429 - 2³ = 1281136421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281136421) 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, 658729 + ... + 660670.

It is an arithmetic number, because the mean of its divisors is an integer number (320614200).

Almost surely, 2^1281136429 is an apocalyptic number.

It is an amenable number.

1281136429 is a deficient number, since it is larger than the sum of its proper divisors (1320371).

1281136429 is an equidigital number, since it uses as much as digits as its factorization.

1281136429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1320370.

The product of its digits is 20736, while the sum is 37.

The square root of 1281136429 is about 35792.9661944913. The cubic root of 1281136429 is about 1086.0882789748.

The spelling of 1281136429 in words is "one billion, two hundred eighty-one million, one hundred thirty-six thousand, four hundred twenty-nine".