1209129541 has 4 divisors (see below), whose sum is σ = 1221594892. Its totient is φ = 1196664192.

The previous prime is 1209129533. The next prime is 1209129553. The reversal of 1209129541 is 1459219021.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 284057316 + 925072225 = 16854^2 + 30415^2 .

It is a cyclic number.

It is not a de Polignac number, because 1209129541 - 2³ = 1209129533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1209129497 and 1209129506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1209129521) 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, 6232530 + ... + 6232723.

It is an arithmetic number, because the mean of its divisors is an integer number (305398723).

Almost surely, 2^1209129541 is an apocalyptic number.

It is an amenable number.

1209129541 is a deficient number, since it is larger than the sum of its proper divisors (12465351).

1209129541 is an equidigital number, since it uses as much as digits as its factorization.

1209129541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12465350.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 1209129541 is about 34772.5400423955. The cubic root of 1209129541 is about 1065.3466484547.

The spelling of 1209129541 in words is "one billion, two hundred nine million, one hundred twenty-nine thousand, five hundred forty-one".