31428197 has 4 divisors (see below), whose sum is σ = 31440396. Its totient is φ = 31416000.

The previous prime is 31428191. The next prime is 31428253. The reversal of 31428197 is 79182413.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 79182413 = 17 ⋅4657789.

It can be written as a sum of positive squares in 2 ways, for example, as 2709316 + 28718881 = 1646^2 + 5359^2 .

It is a cyclic number.

It is not a de Polignac number, because 31428197 - 2⁸ = 31427941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31428191) 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, 554 + ... + 7947.

It is an arithmetic number, because the mean of its divisors is an integer number (7860099).

Almost surely, 2^31428197 is an apocalyptic number.

It is an amenable number.

31428197 is a deficient number, since it is larger than the sum of its proper divisors (12199).

31428197 is an equidigital number, since it uses as much as digits as its factorization.

31428197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12198.

The product of its digits is 12096, while the sum is 35.

The square root of 31428197 is about 5606.0857110822. The cubic root of 31428197 is about 315.5778324706.

The spelling of 31428197 in words is "thirty-one million, four hundred twenty-eight thousand, one hundred ninety-seven".