31205226028861 has 4 divisors (see below), whose sum is σ = 31491512506300. Its totient is φ = 30918939551424.

The previous prime is 31205226028843. The next prime is 31205226028877. The reversal of 31205226028861 is 16882062250213.

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 26896359268900 + 4308866759961 = 5186170^2 + 2075781^2 .

It is a cyclic number.

It is not a de Polignac number, because 31205226028861 - 2²³ = 31205217640253 is a prime.

It is a super-2 number, since 2×31205226028861² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31205226028841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143143238556 + ... + 143143238773.

It is an arithmetic number, because the mean of its divisors is an integer number (7872878126575).

Almost surely, 2^{31205226028861} is an apocalyptic number.

It is an amenable number.

31205226028861 is a deficient number, since it is larger than the sum of its proper divisors (286286477439).

31205226028861 is a wasteful number, since it uses less digits than its factorization.

31205226028861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286286477438.

The product of its (nonzero) digits is 552960, while the sum is 46.

The spelling of 31205226028861 in words is "thirty-one trillion, two hundred five billion, two hundred twenty-six million, twenty-eight thousand, eight hundred sixty-one".