1231540202 has 4 divisors (see below), whose sum is σ = 1847310306. Its totient is φ = 615770100.

The previous prime is 1231540183. The next prime is 1231540213. The reversal of 1231540202 is 2020451321.

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

It can be written as a sum of positive squares in only one way, i.e., 829497601 + 402042601 = 28801^2 + 20051^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 307885049 + ... + 307885052.

Almost surely, 2^1231540202 is an apocalyptic number.

1231540202 is a deficient number, since it is larger than the sum of its proper divisors (615770104).

1231540202 is an equidigital number, since it uses as much as digits as its factorization.

1231540202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615770103.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 1231540202 is about 35093.3070826903. The cubic root of 1231540202 is about 1071.8883015766. Note that the first 3 decimals are identical.

Adding to 1231540202 its reverse (2020451321), we get a palindrome (3251991523).

The spelling of 1231540202 in words is "one billion, two hundred thirty-one million, five hundred forty thousand, two hundred two".