28040997 has 4 divisors (see below), whose sum is σ = 37388000. Its totient is φ = 18693996.

The previous prime is 28040993. The next prime is 28041011. The reversal of 28040997 is 79904082.

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 not a de Polignac number, because 28040997 - 2² = 28040993 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 (28040993) 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, 4673497 + ... + 4673502.

It is an arithmetic number, because the mean of its divisors is an integer number (9347000).

Almost surely, 2^28040997 is an apocalyptic number.

It is an amenable number.

28040997 is a deficient number, since it is larger than the sum of its proper divisors (9347003).

28040997 is an equidigital number, since it uses as much as digits as its factorization.

28040997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9347002.

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 28040997 is about 5295.3750575384. The cubic root of 28040997 is about 303.8070285309.

The spelling of 28040997 in words is "twenty-eight million, forty thousand, nine hundred ninety-seven".