1231542011 has 4 divisors (see below), whose sum is σ = 1407476592. Its totient is φ = 1055607432.

The previous prime is 1231541989. The next prime is 1231542029. The reversal of 1231542011 is 1102451321.

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

It is a cyclic number.

It is not a de Polignac number, because 1231542011 - 2¹⁰ = 1231540987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231542311) 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, 87967280 + ... + 87967293.

It is an arithmetic number, because the mean of its divisors is an integer number (351869148).

Almost surely, 2^1231542011 is an apocalyptic number.

1231542011 is a deficient number, since it is larger than the sum of its proper divisors (175934581).

1231542011 is an equidigital number, since it uses as much as digits as its factorization.

1231542011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175934580.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1231542011 is about 35093.3328568262. The cubic root of 1231542011 is about 1071.8888264058. Note that the first 4 decimals are identical.

Adding to 1231542011 its reverse (1102451321), we get a palindrome (2333993332).

The spelling of 1231542011 in words is "one billion, two hundred thirty-one million, five hundred forty-two thousand, eleven".