131231023402 has 4 divisors (see below), whose sum is σ = 196846535106. Its totient is φ = 65615511700.

The previous prime is 131231023379. The next prime is 131231023457. The reversal of 131231023402 is 204320132131.

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., 120229321081 + 11001702321 = 346741^2 + 104889^2 .

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, 32807755849 + ... + 32807755852.

Almost surely, 2^131231023402 is an apocalyptic number.

131231023402 is a deficient number, since it is larger than the sum of its proper divisors (65615511704).

131231023402 is an equidigital number, since it uses as much as digits as its factorization.

131231023402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65615511703.

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 131231023402 its reverse (204320132131), we get a palindrome (335551155533).

The spelling of 131231023402 in words is "one hundred thirty-one billion, two hundred thirty-one million, twenty-three thousand, four hundred two".