28997501 has 4 divisors (see below), whose sum is σ = 31228092. Its totient is φ = 26766912.

The previous prime is 28997491. The next prime is 28997531. The reversal of 28997501 is 10579982.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17935225 + 11062276 = 4235^2 + 3326^2 .

It is a cyclic number.

It is not a de Polignac number, because 28997501 - 2¹⁰ = 28996477 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 (28997531) 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, 1115276 + ... + 1115301.

It is an arithmetic number, because the mean of its divisors is an integer number (7807023).

Almost surely, 2^28997501 is an apocalyptic number.

It is an amenable number.

28997501 is a deficient number, since it is larger than the sum of its proper divisors (2230591).

28997501 is a wasteful number, since it uses less digits than its factorization.

28997501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2230590.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 28997501 is about 5384.9327758107. The cubic root of 28997501 is about 307.2228573499. Note that the first 3 decimals are identical.

The spelling of 28997501 in words is "twenty-eight million, nine hundred ninety-seven thousand, five hundred one".