28581576397 has 4 divisors (see below), whose sum is σ = 31179901536. Its totient is φ = 25983251260.

The previous prime is 28581576391. The next prime is 28581576403. The reversal of 28581576397 is 79367518582.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (28581576391) and next prime (28581576403).

It is a cyclic number.

It is not a de Polignac number, because 28581576397 - 2⁷ = 28581576269 is a prime.

It is a super-3 number, since 3×28581576397³ (a number of 32 digits) contains 333 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 (28581576391) 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, 1299162553 + ... + 1299162574.

It is an arithmetic number, because the mean of its divisors is an integer number (7794975384).

Almost surely, 2^28581576397 is an apocalyptic number.

It is an amenable number.

28581576397 is a deficient number, since it is larger than the sum of its proper divisors (2598325139).

28581576397 is a wasteful number, since it uses less digits than its factorization.

28581576397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2598325138.

The product of its digits is 25401600, while the sum is 61.

The spelling of 28581576397 in words is "twenty-eight billion, five hundred eighty-one million, five hundred seventy-six thousand, three hundred ninety-seven".