28172249397 has 48 divisors (see below), whose sum is σ = 43379601408. Its totient is φ = 17557102080.

The previous prime is 28172249389. The next prime is 28172249401. The reversal of 28172249397 is 79394227182.

It is a happy number.

28172249397 is a `hidden beast` number, since 2 + 8 + 1 + 7 + 2 + 249 + 397 = 666.

It is not a de Polignac number, because 28172249397 - 2³ = 28172249389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28172249797) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16939788 + ... + 16941450.

It is an arithmetic number, because the mean of its divisors is an integer number (903741696).

Almost surely, 2^28172249397 is an apocalyptic number.

It is an amenable number.

28172249397 is a deficient number, since it is larger than the sum of its proper divisors (15207352011).

28172249397 is a wasteful number, since it uses less digits than its factorization.

28172249397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2370 (or 2367 counting only the distinct ones).

The product of its digits is 3048192, while the sum is 54.

The spelling of 28172249397 in words is "twenty-eight billion, one hundred seventy-two million, two hundred forty-nine thousand, three hundred ninety-seven".