28750997 has 4 divisors (see below), whose sum is σ = 31364736. Its totient is φ = 26137260.

The previous prime is 28750987. The next prime is 28751003. The reversal of 28750997 is 79905782.

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 a cyclic number.

It is not a de Polignac number, because 28750997 - 2⁸ = 28750741 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 (28750987) 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, 1306853 + ... + 1306874.

It is an arithmetic number, because the mean of its divisors is an integer number (7841184).

Almost surely, 2^28750997 is an apocalyptic number.

It is an amenable number.

28750997 is a deficient number, since it is larger than the sum of its proper divisors (2613739).

28750997 is a wasteful number, since it uses less digits than its factorization.

28750997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2613738.

The product of its (nonzero) digits is 317520, while the sum is 47.

The square root of 28750997 is about 5361.9956173052. The cubic root of 28750997 is about 306.3498249059.

Adding to 28750997 its sum of digits (47), we get a square (28751044 = 5362²).

The spelling of 28750997 in words is "twenty-eight million, seven hundred fifty thousand, nine hundred ninety-seven".